November 2007 - test-drb@ccmp.vtda.org

by dgriffi＠cs.csubak.edu

I have an Intel MDS that needs special care. As you may have heard, I was in a car accident at the beginning of last month. The main casualty, except for the car, was an Intel MDS. I offered it to the Computer History Museum and was turned down because they don't have anyone who understands the MDS well enough to attempt to restore it. Please take a look at photos of the machine[1]. I can't really let this go for free because I promised its owner that I would sell it, so please offer something decent. Except for the lid of one chip getting knocked off, the boards all appear to be intact. The CRT is not cracked and there's no apparent evidence of it being breached. If the floppy drive is bad, I have some replacements. The chassis however, is in sorry condition. It's made of a foamy sort of polymer similar to the stuff used in older Sun workstations. The impact of the crash cleaved the chassis into two pieces: the top containing the CRT and floppy drive and the bottom holding the backplane and cards. No keyboard was present to begin with. This owner is the same one who had the Nova 4 I offered here in September. [1] http://frotz.homeunix.org/mds-damage.jpg -- David Griffith dgriffi at cs.csubak.edu A: Because it fouls the order in which people normally read text. Q: Why is top-posting such a bad thing? A: Top-posting. Q: What is the most annoying thing in e-mail?

17 years, 5 months

4
4
0 0

Intel MDS needs home

by aek＠bitsavers.org

> I offered it to the Computer > History Museum and was turned down because they don't have anyone who > understands the MDS well enough to attempt to restore it. I was one of the people who evaluated the offer, and restoration was NEVER discussed. Anyone who has seen a picture of what you had offered would understand why. I've seen gear in dumpsters that look better than that MDS.

17 years, 5 months

5
4
0 0

Commodore PET

by dm561＠torfree.net

Date: Fri, 9 Nov 2007 17:45:36 +1300 From: Ethan Dicks <ethan.dicks at usap.gov> Subject: Re: Commodore PET <snip> >I wouldn't mind getting a chicklet-keyboard PET (I sold that $100 one >I had a few years back for slightly more than I paid), <snip> Hey, where's my cut? Seems to me I sold you a like-new chiclet keyboard for that baby for a song... ;-) <snip> >I'd probably seriously consider a broken PET with a shell in good shape, >since I'm confident of my abilities to diagnose bad RAMs, bad sockets, etc. <snip> If you find a shell and need a board I've got a nice challenge for ya: a 2001 mobo that someone started to convert to 64K dynamic RAMS... mike

17 years, 5 months

2
1
0 0

MC68000 "size" (was Re: modern serial terminal)

by lee＠geekdot.com

> There's a reason I described the 68000 as a 16/32 processor earlier > today... internally it *is* 32 bits. The bus interface is just reduced > to save on the pin count, etc. > Look at the size of the ALU and the accumulator(s)/data registers, then > come back to me. The MC68000 only has a 16 bit ALU and longword operations are done in low/high word sequence. This is why some longword operations take two more cycles than their equivalent word forms. Lee.

17 years, 5 months

8
9
0 0

trs80 items wanted

by jwest＠classiccmp.org

At VCFX I was able to get the last major component for my TRS80 setup (already have the monitor, drives, and expansion interface). I got the keyboard unit for $20. Looks like all I'm missing is a real tandy power supply for the Model 1 (yes, I know I can rig something up, but I'm looking for the real mccoy), and the buffered cable between keyboard and expansion interface. Anyone have one of those two items and is willing to trade? Jay West

17 years, 5 months

1
0
0 0

Slightly OT: Mac help needed near Detroit

by evan＠snarc.net

Someone please help my friend Peter. He's outside of Detroit and needs to move some files from a Mac IIsi, onto CD, to use inside a (presumably modern) version of Windows. Email him directly. - Evan <mailto:Spetereckstein at comcast.net> petereckstein at comcast.net I am having a very hard time translating Mac files that I have on a CD into a Windows format. I have found a Mac IIsi computer that works well, but it only receives input from floppies. This may solve much of my problem, since a lot of my old work was preserved on floppies, but I still could use an external drive device that would let me import data >from my CD to my IIsi. If you have any associates in MI who might be able to sell--or even to lend--me an old external CD drive, I would appreciate learning a name or two. I am in Ann Arbor, broadly speaking in the Detroit area.

17 years, 5 months

1
0
0 0

8" disks from athana

by grant＠stockly.com

Has anyone bought disks from http://www.athana.com ? I'm pretty sure I sent a price quote request in before, but don't remember hearing anything back. I just sent in another. What kinds of prices do these guys have? Anywhere else that has new 32 hard sectored 8" disks for sale? Grant

17 years, 5 months

9
14
0 0

Unix on 32016

by aek＠bitsavers.org

> I don't think anyone else managed a port to that particular CPU National ported 4.1 to it. Their version is called Genix.

17 years, 5 months

6
6
0 0

VCF News Video

by marvin＠west.net

Someone just sent me a link to a C/Net video covering this years VCF: http://www.news.com/1606-2-6217243.html

17 years, 5 months

1
0
0 0

An old dream come true: Iris Indigo!

by compoobah＠valleyimplants.com

On Nov 8, 2007, at 9:42 AM, cctalk-request at classiccmp.org wrote: > Yup. I realized after posting that message that 'SIMM' can simply be > viewed a general form-factor. However, more commonly it's applied to > the > 30pin or 72pin PeeCee variety. > > I've seen SIMM adapters that allow you to stack multiple 30pin modules > on > a a 72pin socket. Did anyone ever make a converter for any > workstations > that would support using garden variety memory in, e.g. an older Iris? > > Steve Nope, the IP12 SIMMS have an ASIC on board to handle (something semi-undocumented). Looks like the SIMMS are 16-bits wide, too (2 rows of 9 chips, with 2 of the chips a different capacity). Anyone tooling up to make an adaptor might as well go ahead and make the SIMMS and spare the physical install hassles (an adaptor probably wouldn't work in an Indigo). I have some 2MB IP12 SIMMS that I've been mulling over the possibility of putting higher capacity chips on, but I don't know if I have chips to deal with the different-sized ECC/Parity (probably, making a guess here though) components.

17 years, 5 months

1
0
0 0

Tarbell is making me insane

by ajp166＠bellatlantic.net

> >Subject: Tarbell is making me insane > From: Grant Stockly <grant at stockly.com> > Date: Tue, 06 Nov 2007 23:07:13 -0900 > To: cctalk at classiccmp.org > >I'm about to go insane. > >Here is what I have: >-Fake Altair (rock solid in everything but tarbell) >-Tarbel 1011D >-Tarbell 1011A, which SEEMS to be better than the 1011D. >-4xMITS 16MCS 16k memory cards >-5xSEALS 8k SRAM >-2SIO >-MITS Rev0 CPU > >Anyway...it doesn't work at all if I have a 16k memory card and an 8k >memory card. The 1011A works best (gets the furtherest in all >tests). If I'm lucky it asks me how many disks I have! > >It also doesn't work with 3 seals 8k cards. > >When I put in a CompuPro active terminator on the end of the bus, the >computer goes crazy and doesn't do anything. Installing an >"Industrial Micro Systems" terminator from 1980 it changes >operational characteristics, but still doesn't quite do it. > >I had been trying to make the stupid thing work for months, on and off... > >Well, I decided to stop trying to limit the number of cards on the >bus. I put in 5 8k seals cards and the stupid thing boots and runs >commands. Before while loading BDOS it would most of the time report >corrupted or missing sectors. Or just print trash. Now I can run >DISKDMP and programs like that. > >After working flawlessly for a few minutes its back to crazy. I can >single step through the tarbel boot program and see it going crazy... : ( > >I'd like the thing to be rock solid with minimal memory cards. > >Can anyone think of WHY the tarbel card is so much trouble? I burn >EPROMs all day long with this Altair. It takes 3 minutes to burn a >1702 and I've never had one fail! I can also leave it playing music >for all night long with no problems!!! > Welcome to S100. First ANY CARD that uses wait (many disk controllers stall the cpu waiting for data) will tend to corrupt Dram depening on the DRAM card and timing. I found 884MCDs problematic until I converted them to a pin compatable static rams. The S4Ks sorta worked but not with DMA. I don't have info on tarbel 1011 seris FDC. The schematic on hand I could comment more. However 8" DD with 2mhz 8080 is very difficult to do as single density is already pushing the 8080 through some very tight software loops. Of all the cards the SEALs 8k and the PT 8Ks were about the best. Also sounds like oneshot problems. Check cpu timing. Even small timing errors tend to magnify bus noise issues and incompability problems. Some cards were timing incompatable due to how they decoded status signals and tended to be either sensitive to bus noise or cause bus noise. Also HEAT. That thing despite a very heafty noisy fan and cover mods didn't like heat. FYI: the timing of the oneshots drifts with heating! In general It sounds like the usual problems I had with the Altair prior to retirement. It was always conditionally stable, make a change start over again. It Improved when I replace the CPU one shot clock with an 8224, better still with a WAMCO "quiet mother" backplane and improved more when I went to a Z80 card (NS* ZPB). near the end the only thing stock was the front pannel (even the connecting leads were shortend and extra grounds added). The 8800BT has none of these problems, It has both tarbell and MITS floppy controllers. Allison > >I need help!!! : ( > >Grant

17 years, 5 months

5
5
0 0

Tandy Logix-Kosmos (was: Re: Ferranti Logical Computor (1951) )

by blstuart＠bellsouth.net

> > http://oldcomputermuseum.com/logix_kosmos.html > > That was the first one I had - the overlays inside were, IIRC, printed > tissue paper. Me too. I still remember how I would forget that they were not symmetric, so if you put them in backwards the separators between the output values and the plastic separators between the lights don't line up. > > Mine died of corrosion on the contacts, and was (regrettably) > > trashed, I'm pretty sure. > > I remember the contacts weren't great on the best of days. I think my > step-mother threw mine out when she decided my room was too messy. > :-( Yeah. The contacts were my biggest source of frustration. I probably would have done a lot more with it, if I hadn't had to wiggle wires and adjust the contacts for every "program" on it. Believe it or not, I still have mine. I even have it upstairs where I can find it. Not that I've used it any time recently. > My only real complaint with it as a teaching tool was that even though > I did all the projects, there was no abstraction of the underlying > concepts presented. I agree. They also didn't do a good job of clarifying that the device only implemented combinatorial logic. As I recall, I got it before the idea of a stored program really clicked with me. Unless I missed it, they didn't have a discussion in the manual that said, this "computer" does this, but real computers also have memory that stores not only data, but instructions too. BLS

17 years, 5 months

4
7
0 0

Televideo Terminals TS-800A (UK)

by james＠attfield.co.uk

I have just been told about the availability FOC of the following: 3-off Televideo TS-800A terminals with keyboards (believed RS-232 and believed serviceable) 2-off IBM Monitors 5153 (condition unknown but I had one a while back and it was serviceable) 2-off IBICO printer calculators 1050 and 1060 (condition unknown) These are headed for the dump unless a home is found fairly quickly. I don't have a need but will gladly put any takers in touch with the owners or in a pinch will collect and store for a short time pending final collection. Sorry, no shipping possible or arrangements outside the UK. Current location is Coventry (UK) but equipment can be relocated to Redditch (UK) or Stourbridge, West Midlands (UK). I don't imagine the current owners will be keen on protracted or complex arrangements as they just want rid so preference is likely to be given to someone willing to take the lot. A chit will need to be signed affirming the kit has been removed so that the owners can substantiate that it has not just been dumped for audit purposes. Any interested parties should email me off-list at james/at/attfield/dot/co/dot/uk. Please be quick - I'm pretty sure it won't be kept for long. Jim This outbound email was scanned by Norton AntiVirus 2007 when transmitted and all reasonable precautions have been taken to ensure that this email was free of current known viruses and other malware when sent. Please be aware that between here and you are an indeterminate number of email relays so you should not rely wholly on this and ensure that you have adequate up-to-date protection against viruses, worms, spyware and trojans etc. The sender can not be held responsible for any undesirable elements or malware in a received email sent by him. Please note that if your reply originates from GOOGLE, HOTMAIL, MSN or YAHOO it may never reach me as these domains are blocked.

17 years, 5 months

4
3
0 0

Commodore 64 MIDI workstation?

by woyciesjes＠sbcglobal.net

ISTR a web page I saw the otehr day, where a guy showed how to modify a Commodore 64 to do stereo output, made the case smaller, etc. Does this ring a bell with anyone here? -- --- Dave Woyciesjes --- ICQ# 905818 --- AIM - woyciesjes "From there to here, From here to there, Funny things are everywhere." --- Dr. Seuss

17 years, 5 months

4
4
0 0

TS03

by tponsford＠rnsmte.com

Hi All Picked up a good lot of pdp stuff at the auction yesterday a Netcom 11/23, and a H960 rack which I've been looking for to put my 11/04 in. As a bonus, the rack came with a TS03 which I've read is a re badged Kennedy 9700, a 9-track tape drive w/ 7" reels. The rack had the expansion Unibus box with the TMB11 interface, Doesn't the TS03 have a pertec interface and if it does, wouldn't a third party emulex or diloq unibus card work? Any advice or gotchas on this tape drive would be appreciated!! Cheers Tom Ponsford

17 years, 5 months

2
1
0 0

Kaypro 4/84 questions

by ajp166＠bellatlantic.net

> >Subject: Re: Kaypro 4/84 questions > From: Brian Wheeler <bdwheele at indiana.edu> > Date: Wed, 07 Nov 2007 11:26:54 -0500 > To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> > >On Mon, 2007-11-05 at 17:54 -0400, Roy J. Tellason wrote: >> On Monday 05 November 2007 13:13, Brian Wheeler wrote: >> > * I'd like to replace the 2nd drive with a 3.5" floppy. I've found a >> > Sony HD drive along with a power and plug converter. Knowing that PCs >> > use a twisted cable scheme, what things should I be aware of when >> > cabling in this new drive? >> >> The twist in the cable was to not have to worry about jumper settings which >> you had to deal with prior to that point. Those drive select jumpers are >> marked, depending on the brand, either 0-3 or 1-4 on the drive electronics, >> with the first two choices being the ones commonly used (0 and 1, or 1 and >> 2). The cable with the twist setup has both drives set to the second choice, >> so you probably won't need to worry about messing with anything there, >> selecting the drive should be apparent as Kaypros tend to leave the light on >> all the time. >> >> > Will it be supported in some manner by the software? >> >> Hm, kinda doubtful, though I couldn't say for sure as it's been a long time >> since I dove into those particular interface specs. >> >> > Its not a big deal if it turns out to be a 360K 3.5" floppy, as long as its >> > readable by my linux box. >> >> That might just be what you end up with. Do tell us when you find out, I'd >> be curious to know... >> > >I've got the 3.5" drive installed and cabled and it seems to be working >rather well. I ended up using vice grips to get the screws loose in the >drive cage since the heads kept wanting to strip. As I suspected, it >really thinks its just a DSDD 5.25" drive. I formatted a disk using >mfdisk as an IBM 9 sector DS disk and could read it (as 360K) without >problems on my linux box. > >The drive I ended up using was a chinon FZ-357 which has a jumper for >RDY as well as drive select jumpers. It also had the interface pins on >the same side as the original disk so I could use the original cable. >All of my other 3.5" drives had it on the other side, but the cable >wasn't long enough to shift sideways enough. > >Its weird when it does a format since it counts tracks from 0 to 79 but >its really counting cylinder 1 as tracks 0 and 1, etc. > >However, trying to read a kaypro formatted disk isn't working. It reads >4K and then fails. Anybody used setfdprm on linux to set up reading >kaypro iv/10 disks? They look like they're 10 sector (numbered 0x0a - >0x13), rate=2 disks. You may have to notify the software of what format is being used. >I'll probably mount the 5.25" DSDD drive in my linux box as well, but >it'd be nice to know how to read disks without hassle :) > >Now for some more questions: > >* is it possible to run CP/M 3.x on it, or am I limited to 2.2G? Yes, but without any banked memory. >* what's the J9 header for? It looks like it has 8 data bits and 8 >address bits wired to it (at least according to the schematics I've >found). Seems like it'd be possible to hang a home-made IDE interface >onto it (if I ever get time/inclination) Its host interface for WD1001HDO HDC, Sorta like IDE save for the board was bigger than the drive, it wasn't integrated, it was 8bit and the registers were slightly differnt. To do IDE with that should be easy as its basiccally the process or bus for IO. There will not be software support (BIOS) unless you do it. Allison > >Thanks to all of the suggestions and advice! > >Brian >

17 years, 5 months

2
1
0 0

cctalk Digest, Vol 51, Issue 18

by compoobah＠valleyimplants.com

On Nov 7, 2007, at 2:00 PM, Chuck wrote: > On 7 Nov 2007 at 10:58, Richard wrote: > >> Umm... IIRC, Xenix was a unix implementation that didn't even require >> virtual memory, ran on x86 architectures (386?) and required very >> little memory; certainly much less than Win96 since Xenix was >> available in 1986. > > Early Xenix ran on a 286. I don't think it ever ran on anything > less. I have an early Microsoft MSDOS 2.0 OEM announcement that > talks about eventually unifying Xenix and MSDOS. I guess that goes > in the same category as Microsoft OS/2 2.0... There were versions for Lisa and (not used but seen pictures of) an 8086 version - perhaps on one of the early Altoses. Later versions of Xenix were 286 and up, and later (with XENIX System V 386) 386 and up.

17 years, 5 months

4
3
0 0

Tarbell is making me insane

by ajp166＠bellatlantic.net

> >Subject: Re: Tarbell is making me insane > From: Grant Stockly <grant at stockly.com> > Date: Wed, 07 Nov 2007 23:35:01 -0900 > To: "General Discussion: On-Topic Posts Only" <cctech at classiccmp.org> > > >>Changing the crystal would half the data rates making it right for >>5.25" floppy. >> >>One of the modes all the contrllers that use hang mode (wait), is >>sector never found. Wrong clock rate will insure that. > >I was also considering that at 2MHz instead of 4 the FDC controller >will be operating close to its limits and may need the wait >state. What was happening was probably a missed wait state. More like the data rate for the board was halved 250kbits/sec and the data was never being read. That will hang the system as the FDC is waiting for the data and at the wrong rate it will never arrive. The Clock crystal is used to derive the data rate for reading and writing. >>Both work. The logic however uses the 8T97 and tristates it when >>not needed (board not addressed) which is a "legal" way to do it >>though it seems like more effort. >> >>Of course using high is active and mixing than with low is active was >>a dumb thing too. Even Tristate asserts a better low than a high. > >The front panel buffer is hard wired on, so the Tarbell was shorting >out the panels XRDY. That too. On front pannelless systems thats not an issue. > >I reviewed the 1k memory card and it does tristate it like you >said. My problem with the 1k card way back then was that the MITS >documentation puts both on the PRDY line. In my two systems this was >no good. The transients would corrupt the bus cycle. This was found >when working with an altair laying on a wooden table. It wasn't in a >metal case. I never tried putting both on the PRDY line when it was >in an enclosure. I imagine it would have worked better in the case >since I've never read any errata on it, but I wanted to play it safe. It would ahve worked btter is the rams used wer 600ns rather than 1uS and the wate states never needed. >If you want to talk about media abuse...1.4MB disk with the HD hole >covered, formatted to 71k : ) That works. > >One of my problems MIGHT have to do with the 16v and 8v supplies not >turning on at the same time. I will have to investigate that more... Why do they not turn on at the same time? All the altairs I know of the switch was on the AC side and it all came up soon as AC was applied. Allison

17 years, 5 months

1
0
0 0

VCF: 5100 emulator?

by frustum＠pacbell.net

I recall seeing that someone was going to show off their software emulation of the IBM 5100 computer at the VCF that just happened. Did it make an appearance? I just checked the VCF exhibitor list and didn't see it there anymore. Was it retracted? Does anybody know who developed it? I'm quite curious to learn more about it; writing such an emulator was on my long term TODO list, but I'm glad somebody beat me to it, as there are many other projects on that same list. Thanks.

17 years, 5 months

3
2
0 0

modern serial terminal

by mark＠wickensonline.co.uk

I have an Axel Platine terminal that seems to fit all the requirements - except maybe that the terminal emulation for older computers might be a bit lacking. Size of a 'Letter/A4' piece of paper, an inch thick, uses standard PC keyboard/monitor/LCD and uses 8W of power. They can be bought cheaply of EBay (in the UK anyway) Just a thought Mark

17 years, 5 months

1
0
0 0

Tarbell is making me insane

by ajp166＠bellatlantic.net

> >Subject: Re: Tarbell is making me insane > From: Grant Stockly <grant at stockly.com> > Date: Wed, 07 Nov 2007 12:07:22 -0900 > To: "General Discussion: On-Topic Posts Only" <cctech at classiccmp.org>, > Pete <petechapman at frontiernet.net> > > >>Welcome to S100. >> >>I don't have info on tarbel 1011 seris FDC. The schematic on hand I >>could comment more. However 8" DD with 2mhz 8080 is very difficult >>to do as single density is already pushing the 8080 through some very >>tight software loops. > >I think the crystal on the tarbell has been changed from 4MHz to >2MHz. I do know that one of the failure modes is for the Tarbell to >"crash" within a wait state. Changing the crystal would half the data rates making it right for 5.25" floppy. One of the modes all the contrllers that use hang mode (wait), is sector never found. Wrong clock rate will insure that. >I read the manual and when it started talking about not using >"Active" wait state generation I was given a hint. > >The tarbell as I received it was using XRDY for wait states. My >front panel uses XRDY. > >When I was developing the Altair kit I found that the 1k memory card >would NOT deposit or examine because the PRDY was being driven by the >front panel. The 1k memory card would have to basically over power >the front panel buffer. This would cause some nice transients too. > >So this morning I changed the tarbell from XRDY to PRDY and it >worked. It has worked fine every time I have tried it since, so >maybe I found the 'BUG'. It's always Prdy. The 1K card uses it becuse the rams installed were Sllooowwww and wait states were needed. I'd not use that card ever. When using A FDC that asserts wait for syncronization you really don't want memory that insert wait states as the CPU is alreay slow enough and slow memory is a bad thing. >So, WHY do all these old cards use 8T97 type drivers to force the >wait line? I guess its only the MITS display board and 1k memory >board that drive the wait line regardless of if they are addressed or >not. Whats wrong with these guys using open collector parts with a pullup??? Both work. The logic however uses the 8T97 and tristates it when not needed (board not addressed) which is a "legal" way to do it though it seems like more effort. Of course using high is active and mixing than with low is active was a dumb thing too. Even Tristate asserts a better low than a high. >I'll report on how robust it is later on. I've had several false >starts with this setup... > >>Also sounds like oneshot problems. Check cpu timing. Even small timing >>errors tend to magnify bus noise issues and incompability problems. > >I checked that. Good, keep checking it as those oneshots are not reliable in my book. Allison >Grant

17 years, 5 months

2
1
0 0

Indigo 2 and registered/buffered SIMMs.

by compoobah＠valleyimplants.com

On Nov 7, 2007, at 8:19 AM, cctalk-request at classiccmp.org wrote: > Memory for Indigo 2 (IP22) needs to be FPM with ECC. But I couldn't > find anywhere if these SIMMs may be "registered", aka "buffered". > I see quite a few cheap FPM ECC SIMMs for sale, but most of them have > some strange additional chips on them, I guess that means there are > of the buffered kind. Will these modules work in I2? > FPM 36-bit (often called parity). I have seen on the Internet reports that the IP22 gangs them together similar to the way DEC does with some 21164 machines to get ECC, but skimming the documentation for the MC1 and DMUX1 doesn't make reference to this, merely "parity". There are other 72-pin SIMMS (such as the IBM RS/6000 ones) that are ECC, so make sure that you're not trying to use one of these (ECC uses a different pinout). They don't need to be buffered (only 3 banks). Regarding the Indigo: Indigo R3k uses SGI-proprietary IP12 SIMMS (shared with the 4D/30 and /35). Indigo R4k has the same memory controller as IP22 Indigo2, and uses 36-bit 72-pin SIMMs.

17 years, 5 months

1
0
0 0

modern serial terminal

by ajp166＠bellatlantic.net

> >Subject: Re: modern serial terminal > From: woodelf <bfranchuk at jetnet.ab.ca> > Date: Wed, 07 Nov 2007 19:43:05 -0700 > To: General Discussion: On-Topic and Off-Topic Posts <cctalk at classiccmp.org> > >Jim Leonard wrote: >> So what's your thoughts on the 8088? 16-bit registers, 8-bit data path >> (but with 16-bit addressing). Is it a 16-bit CPU or an 8-bit CPU? >8 bit CPU with 16 bit instructions. :( Both 8088 and 8086 are 16bit cpus, also 80188 and 80186 they differ only in external bus width. That bus width has no programatic effect in that binaries are the same for both. Internal register sizes are same for both flavors. The 68K also had the 68008 a 32bitter that had a narrow data bus. DEC T-11 (PDP-11) also had the option at reset time to configure the bus as 8bit wide or 16bit. The Z280 also had this option. However the T-11 is without question 16bits and the Z280 is 8bit. The 386SLC and 486slc were both 32bit but had a 16bit wide bus for interface convenience. The point is bus width only determins bus bandwidth and performance and is not the say all for "xx width" cpu. Allison

17 years, 5 months

1
0
0 0

Kaypro 4/84 questions

by bdwheele＠indiana.edu

I recently acquired a Kaypro 4/84 and I'm in the process of cleaning it up and getting it happy. There are a couple of problems with it that maybe someone can shed some light on: * one of the keyboard latches is broken. Anyone know a good substitute and/or workaround? I don't care so much about it, but it'd be nice to be able to lug it into the kitchen and carry something else at the same time :) * They keyboard cable is missing, but I substituted a keyboard cable >from a DEC terminal keyboard and it seems to work. The tech manual I found online says that using a phone cord causes dropped characters due to the smaller wire gauge, so I'm hoping that this cable will be sturdy enough. * There is a screw in the 2nd floppy drive opening. I've tried removing the drive sled (via the screws on the bottom), but alas it seems like the drives have to come out of the front individually. The screws are pretty solidly inserted and I cannot get them loose without stripping them. I'm not able to get to the inner ones easily without removing the motherboard and the monitor. Is it possible to take the bezel off of the drive and then slide the cage backward and then out? The drives are the shugart ones. * I'd like to replace the 2nd drive with a 3.5" floppy. I've found a Sony HD drive along with a power and plug converter. Knowing that PCs use a twisted cable scheme, what things should I be aware of when cabling in this new drive? Will it be supported in some manner by the software? Its not a big deal if it turns out to be a 360K 3.5" floppy, as long as its readable by my linux box.

17 years, 5 months

4
10
0 0

PC AT Rom Patch?

by cclist＠sydex.com

To follow up, it seems as if the code at offset 058Dh in the Version 3 PC AT BIOS is the speed-tester. Curiously, it seems not simply to test for an overfast CPU clock, but a slow one also. The timebase for the check is the "refresh" bit (bit 4 of port 61h). Values lying outside of the acceptable range result in doing a 0101h beep. A workable patch would seem to be to insert an unconditional jump at 5BC to 5CB, which would bypass both tests. When I get a chance, I'll burn some ROMs and try it, after recomputing the ROM checksum. Cheers, Chuck

17 years, 5 months

2
2
0 0

PERQ Emulator Progress (of sorts)!

by derschjo＠msu.edu

Sorry, I just had to share this with someone, and I thought some of you guys might appreciate it... I've been working on a Three Rivers PERQ emulator since last year in my spare time, though I've had basically no time the past eight months or so. Last I left the code, it managed to boot POS about halfway before the boot process would hang. Well, I managed to fix (or at least, work around) the bug causing the hang, which brought me to this: http://yahozna.dyndns.org/projects/PERQemu/PERQ-3.png Ok, it doesn't look like _much_, but compare it with the photo here: http://yahozna.dyndns.org/computers/perq/photos/pos-boot.jpg (Hint: They're the same thing, only one's really scrambled up :P) The boot process is still erroring out, but it's about 99% there (at DDS 951). Of course, I obviously still have a ways to go. As evidenced by the completely garbled text, I have yet to get the PERQ's unique (and extremely complicated) RasterOp hardware emulated to any significant degree. And after that I have a ton of hardware details to work out. But this is a major milestone, and I'm so excited that I just had to share my excitement with someone... I never thought I'd get anywhere near this far with the emulation, given how complicated the PERQ is. And if I've seen so far, it's because I've been standing on the shoulders of giants. Or one giant, at least -- our own Tony Duell who's been ever-so-patient with my questioning and who probably knows more about the PERQ hardware than the original designers did... Thanks for taking a look, and sorry for tooting my own horn... Josh

17 years, 5 months

3
2
0 0

top2049 programmer as 74xxx chip tester

by lynchaj＠yahoo.com

Hi, Does anyone have any experience with using a TOP2049 as a TTL 74xxx chip tester? How did it work for you? Do you recommend it as a worthwhile piece of test equipment? Thanks! Andrew Lynch

17 years, 5 months

13
24
0 0

TRS-80 Mod 2 Expansion Box

by wdonzelli＠gmail.com

Are the three drive expansion boxes for the TRS-80 Model 2 rare or anything? I have one in pretty rough shape that I plan to part out, but I will hold off if the things are seriously in demand. Let me know in a few hours, as I am loading up to go to the junkyard tomorrow. I also have the TRS-80 Mod 2 computer that I need to test. I do not want it. I would like to sell it or trade it, but I really do not want to pack it. -- Will, in 10512

17 years, 5 months

2
3
0 0

ontopic

by jwest＠classiccmp.org

reminder.... discussions of environmental issues are not freaking on topic!! Do I really have to say that? I'm simply amazed. And then I see quotes from Dr. Who. Un Freaking Believable. J

17 years, 5 months

3
2
0 0

Video of Cray 1 and other artifacts...

by classiccmp＠memory-alpha.org.uk

Hi, >....On Saturday I watched Terminator 3.... My utmost condolences. That's a couple of hours of your life which you'll never get back.... TTFN - Pete.

17 years, 5 months

4
3
0 0

SGI Onyx - Three Phase to Two Phase conversion

by jplist2007＠kiwigeek.com

Greetings all; I'm reading up on the Onyx (rackmount, original Onyx) and the manual says that units with three power supplies (OLS') are configured for three phase, and units with two OLS' are configured for two phase. While my machine does have the optional lower VME card cage and also the second SCSI box (thus necessitating the 3 OLS'), I won't be likely to use either of them. 220v I can do (handy-dandy nearby 40A circuit for a stove) - 3 phase would require wiring changes in the building. Is anyone aware if there was an established procedure to go from 3 phase back to 3 phase on these units? Could I be lucky enough to have someone here who has done it? Thanks! JP Hindin

17 years, 5 months

3
6
0 0

Last call : Flexowriter model 2309 to be scrapped.

by jos.mar＠bluewin.ch

Unless someone takes it off me, a basket case Friden Flexowriter will hit the big smelter in the sky. It is a later model 2309. Location : Zurich Switzerland. Shipping is a no-no. I bought it on ebay for 10$, but it turned out to be more effort to repair than I am willing to invest. BTW the seller compensated me with a nice, functional ASR-33 AND an SWTPC CT1024... Jos

17 years, 5 months

1
0
0 0

WTB: LIM/EMS/XMS 16-bit ISA memory expansion board

by ajp166＠bellatlantic.net

> >Subject: Re: WTB: LIM/EMS/XMS 16-bit ISA memory expansion board > From: "Chuck Guzis" <cclist at sydex.com> > Date: Wed, 07 Nov 2007 10:03:21 -0800 > To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> > >On 3 Nov 2007 at 20:25, Allison wrote: > >> Sounds like someone looking for an ASk 6Pak Pro. > >Do you mean "AST"? Yep. Finally retired the nasty keyboard. > No, not really--I don't need all the other glarf; ;) Well I was hoping.. >just the memory. There was a plethora of makers of memory expansion >boards for the 286. I like the Intel Aboveboards, myself and avoid >the Everex versions, for example. Aboveboard was a good one. I have one paired with with my Intel Inboard386. Allison >Cheers, >Chuck

17 years, 5 months

1
0
0 0

Kaypro 4/84 questions

by ajp166＠bellatlantic.net

> >Subject: Kaypro 4/84 questions > From: Brian Wheeler <bdwheele at indiana.edu> > Date: Mon, 05 Nov 2007 13:13:40 -0500 > To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> > >I recently acquired a Kaypro 4/84 and I'm in the process of cleaning it >up and getting it happy. > >There are a couple of problems with it that maybe someone can shed some >light on: >* one of the keyboard latches is broken. Anyone know a good substitute >and/or workaround? I don't care so much about it, but it'd be nice to >be able to lug it into the kitchen and carry something else at the same >time :) > >* They keyboard cable is missing, but I substituted a keyboard cable >from a DEC terminal keyboard and it seems to work. The tech manual I >found online says that using a phone cord causes dropped characters due >to the smaller wire gauge, so I'm hoping that this cable will be sturdy >enough. The DEC cable is about the best choice available. >* There is a screw in the 2nd floppy drive opening. I've tried removing >the drive sled (via the screws on the bottom), but alas it seems like >the drives have to come out of the front individually. The screws are >pretty solidly inserted and I cannot get them loose without stripping >them. I'm not able to get to the inner ones easily without removing the >motherboard and the monitor. Is it possible to take the bezel off of >the drive and then slide the cage backward and then out? The drives are >the shugart ones. Mine had screws top and bottom. They tended to vary things. >* I'd like to replace the 2nd drive with a 3.5" floppy. I've found a >Sony HD drive along with a power and plug converter. Knowing that PCs >use a twisted cable scheme, what things should I be aware of when >cabling in this new drive? Will it be supported in some manner by the >software? Its not a big deal if it turns out to be a 360K 3.5" floppy, >as long as its readable by my linux box. I've done this using a 3.5" to 5.25" adaptor. The software will not utilize the full 80 tracks of the 3.5" floppy and possibly both sides if the roms are not updated. The Advent turborom with disk personality card and likely others support this. The drives I used had the 1-4 jumper like 5.25" floppies so it was a matter of pin to card edge adaptor, power adaptor and drive select jumper. For later drives you make have no choice but to make a "funny cable" to do drive select. the reason for that is those drives are locked to cable select. Allison

17 years, 5 months

2
1
0 0

PC AT ROM Patch?

by cclist＠sydex.com

I can boot my 10 MHz AT clone with the IBM Version 1 (01/10/84) ROM just fine, but the Version 3 (11/15/85) beeps out a system board error (long-short). I seem to recall that the Version 3 BIOS checked for an 8MHz CPU clock and complained if it was anythng else. I know that the Ver. 2 BIOS checked for a 6MHz clock. Is my memory correct--and does anyone know of a patch? I could do a little digging into the POST code, but I'd rather not duplicate someone else's effort. Cheers, Chuck

17 years, 5 months

1
0
0 0

SGI workstation sequence

by jvdg＠sparcpark.net

Sridhar Ayengar wrote: > David Griffith wrote: >>> I think it goes like this, someone please correct me if I'm wrong: >>> >>> 1984 IRIS (terminal/workstation) >>> 1988? Personal Iris >>> 1990 Indigo >>> 1992 Indigo^2 >>> 1993 Indy >>> 1996 O2 >>> 1999 Octane >>> 2000 Octane2 >>> 2002 Fuel >>> 2003 Tezro >> >> I seem to recall the O2 coming out in 1999, roughly at the same time as >> the Octane. > > Didn't the O2, O20 (Octane), O200 and O2000 come out at roughly the same > time? More or less. Besides that, the Indigo2 and Indy represent a split in the low-end line, both being offspring of the Indigo, with O2 being Indy's successor and Octane being Indigo2's successor. The O200 was the offspring of the Challenge S (and M) low-end server offering. The Fuel and Tezro are also pretty much complementary machines. Also, since Octane sported the Cube logo, I seriously doubt that 1999 introduction date. The logo was changed in 1997/1998 and debuted on the Octane2/O2+ in the IRIS workstation line. Here's the family tree, then: /-> Indigo2 -> Octane -> Octane2 -> Tezro Personal Iris -> Indigo -< \-> Indy -> O2 -> O2+ -> Fuel ,xtG tsooJ

17 years, 5 months

10
28
0 0

List Issues

by ploopster＠gmail.com

Did anyone else just get a flood of older unread emails from the list all at once within the last few hours? Peace... Sridhar

17 years, 5 months

5
4
0 0

An old dream come true: Iris Indigo!

by robinson＠shlrc.mq.edu.au

Hi gang, > > > Can I use a PC mouse/keyboard with that? > > > > You cannot. You need to use a SGI keyboard and mouse. > I have plugged a PC kybd/mouse into a SGI Crimson and an Octane and they seemed to work OK. > > > Are the monitor frequencies suitable for a modern PC monitor? > > > > They aren't. It's sync-on-green, so you either need a good monitor and > > you definitively need an adaptor. > Needed a special cable so I used a Sun cable on the SGI monitor. Worked OK. Have not tried any other monitors. Regards Ray vk2ilv

17 years, 5 months

10
16
0 0

VCFX

by wayne.smith＠charter.net

I have posted some VCFX photos at: http://picasaweb.google.com/Joy.Wayne/VintageComputerFestivalX Labels to follow.

17 years, 5 months

1
0
0 0

8" disk drive project - maybe 3.5" project too???

by ajp166＠bellatlantic.net

> >Subject: Re: 8" disk drive project - maybe 3.5" project too??? > From: Grant Stockly <grant at stockly.com> > Date: Tue, 06 Nov 2007 11:32:34 -0900 > To: "General Discussion: On-Topic Posts Only" <cctech at classiccmp.org> > > >>Write trim erase is a signal to the head assembly (driver) that turns on >>the erase segment of the head for erasing the area either side of the head. >>It's also called tunnel erase. This gives some tolerence to off track reading >>as the intertrack gaps are "clean". Tunnel erase is still part of all >>floppy drives but is activated by Write-enable and you never "hear" of it. >> >>In 1976 all this was new and magical until Sugart came out with the much >>simplified 5.25 SA400. > > From reading the information on the Internet I have pretty much >guessed that much, that it was done automatically on new drives. > >> >Any comments or ideas on the idea? Is it worth trying? I've got a >> >very weird tarbell card that formats and uses 3.5" disks as a 70k >> >mini floppy. I guess anything is possible. : ) >> >>Myself I'd persue something using a 5.25 or 3.5" drive with a current >>softsector interface to the drive and enough CPU smarts to fake looking >>like the Altair interface which was dumb as a rock and depended on the >>8080 to do most everything. > >That is what I was thinking about too. I was thinking about a >controller that hot wired into the existing drive card set. Drive 1 >would activate the fake 3.5" disk or flash memory and drive 0 would >activate the 8" drive for example. That would allow for easy >migration from 8" to a different format. If you can that works. >It would also be nice to have a media readable on a PC. A 3.5" disk >with the fake hard sector formatting wouldn't be possible... Thats impostant as most users will find the availble on media offerings a bit thin is you go with hard sector (faked or real). >What do you think about drive RPM? Should I be able to fake the 32 >hard sectors at any rate I want as long as its as fast or slower than >the 8" drive? I won't touch that. It's one of many warrens and burrows to dive into. >The 3.5" disk should be writing the bits at whatever >bit rate is requested, right? The only reason I want to do the 3.5" >disk interface with faking 32 hard sectors is because it would be a >fast way to get going. Hardly any hardware development required. Drive rpm is always a problem. Even for soft sector the data sep has to deal with that. Faked hard sector is just causing additional pain. Take it from someone that uses a NS* hard sector system where the media and the controller are far more common and pretty reliable and it's a major pain. Media is hard to get and hard sector always was a closed gate to transfering software. I felt the nonportable media was always a major pain and handicap. I still maintain a "stock NS* Horizon" as an artifact but due to media availability and portability my second Horizon that I do use a lot has a softsector controller and hard disk as primary storage. I'd suggest two things: Do complete Altair disk and drives and 1 floppy with it and make additional media the users problem like in 1976, 1980, 1985 and more so now. Or a completely new controller (non replica) that acts like the Altair part (runs unaltered altair basic and all) but is normal softsector using easier to get 5.25 or 3.5 media with portability (and PC as a disk generator) in mind. This would make the system more easily shown and used. Also the user can than have CP/M as well as it was also historically important to any Altair user of the time. Like the 8800BT I have the few that had the Altair contoller usually added a Tarbell or other later on to gain access to the larger software market. Those that started with the base Altair and were slower to go to floppy often didn't even bother with the altair disk and use NS*, Tarbel or one of a handful of others with NS*dos or CP/M as the OS platform. It would be interesting to see how many Altairs (all versions of the 8800) wer sold and then how many disk controllers. I suspect based on my experince of the time it will be something like 20:1 likely greater. The reason was at that time by 1977 the cost differential was fairly great to have Altair floppy disk over brand-x and CP/M was seen a cleary the up and comming OS. It also was a factor that long shipping delays by MITS at times and problems experinced by some tended to push some more toward the after market add ons. My experience, I built and tested the first Altair FDC sold on LI for a company. Just my opinion. Allison >Thanks! > >Grant

17 years, 5 months

1
0
0 0

Hans destroys VAX!

by sellam＠vintagetech.com

Haha! I can't wait to show Hans. He was so embarassingly drunk that night it's not even funny. This happened after I left, and it got much worse. I'm hope no one got on video what I did. -- Sellam Ismail Vintage Computer Festival ------------------------------------------------------------------------------ International Man of Intrigue and Danger http://www.vintage.org [ Old computing resources for business || Buy/Sell/Trade Vintage Computers ] [ and academia at www.VintageTech.com || at http://marketplace.vintage.org ]

17 years, 5 months

1
0
0 0

Tarbell is making me insane

by grant＠stockly.com

I'm about to go insane. Here is what I have: -Fake Altair (rock solid in everything but tarbell) -Tarbel 1011D -Tarbell 1011A, which SEEMS to be better than the 1011D. -4xMITS 16MCS 16k memory cards -5xSEALS 8k SRAM -2SIO -MITS Rev0 CPU Anyway...it doesn't work at all if I have a 16k memory card and an 8k memory card. The 1011A works best (gets the furtherest in all tests). If I'm lucky it asks me how many disks I have! It also doesn't work with 3 seals 8k cards. When I put in a CompuPro active terminator on the end of the bus, the computer goes crazy and doesn't do anything. Installing an "Industrial Micro Systems" terminator from 1980 it changes operational characteristics, but still doesn't quite do it. I had been trying to make the stupid thing work for months, on and off... Well, I decided to stop trying to limit the number of cards on the bus. I put in 5 8k seals cards and the stupid thing boots and runs commands. Before while loading BDOS it would most of the time report corrupted or missing sectors. Or just print trash. Now I can run DISKDMP and programs like that. After working flawlessly for a few minutes its back to crazy. I can single step through the tarbel boot program and see it going crazy... : ( I'd like the thing to be rock solid with minimal memory cards. Can anyone think of WHY the tarbel card is so much trouble? I burn EPROMs all day long with this Altair. It takes 3 minutes to burn a 1702 and I've never had one fail! I can also leave it playing music for all night long with no problems!!! I need help!!! : ( Grant

17 years, 5 months

1
1
0 0

Video of Cray 1 and other artifacts...

by classiccmp＠memory-alpha.org.uk

Hi, >> That's a couple of hours of your life which you'll never get >>back.... > Then I probably should not say that I actually like the movie, have >watched it more then once and that I also own it... :) Sorry, there should've been a smiley on the end of that (I got distracted by a knock at the door). ;-) TTFN - Pete.

17 years, 5 months

1
0
0 0

modern serial terminal

by dgriffi＠cs.csubak.edu

I'm thinking of a device about the size of a couple CD jewel cases that has two serial ports, a ps/2 or usb port, VGA port, power jack, and perhaps a JTAG header concealed within. This device is a regular RS232 serial terminal. Plug in a monitor, keyboard, and something talking rs232 and you're ready to go. Inside there would be a microprocessor, some ram, some flash, and an FPGA to take care of glue logic and talking to the VGA port. The FPGA would be loaded with the digital schematics of a particular terminal and its firmware, for instance, a Wyse 85 or 99GT (my favorites). That would get you most of the usual emulations. How hard would it be to create something like this? How much would it cost? -- David Griffith dgriffi at cs.csubak.edu A: Because it fouls the order in which people normally read text. Q: Why is top-posting such a bad thing? A: Top-posting. Q: What is the most annoying thing in e-mail?

17 years, 5 months

37
108
0 0

Stats on the first known HP Computer at the South Pole

by tsw-cc＠johana.com

> > Jay, other HP fans, > > I finally got a chance to re-examine the article on the wall down here. > > Someone hung up excerpts from "The Antarctic Journal", December 1976, > page 286 (and parts of some presumably nearby pages). The article describes > the "first" computer system at the Pole, which might possibly be true. > During > the 1974/1975 Austral Summer, UC Davis sent down a pair of HP 2100S machines > to Pole. They were both equipped with 32K of memory, and sported paper tape, > at least one line printer, and a pair of 45 ips, 800 bpi magtapes. Other > I/O equipment mentioned in the article include an HP 12930A "universal > interface", at least one HP 2570A "coupler controller", and at least one > HP 12770A serial interface. > > If I run across the original journal, I can see about making scans. Right > now, there is a hodgepodge of xeroxed page fragments taped to the wall. > > Before anyone starts drooling, this gear was all long-gone 20 years after > it was installed. Even the microVAX that was here 10 years ago was packed > up and removed years ago. Closest thing I've seen to a "classic" computer > I've seen in use here lately was a Dell 386SX/16 as the head-end for the PBX > we tore out in 2004, and the Compaq 386N we used for RTTY (last fired up in > 2004 as well). > > It's all modern, boring stuff here now. :-( > > (except for the classic goodies I pack in my luggage ;-) > > -ethan > Wow... Something I know about! I was there for the installation for those computers. They were 2100A's (not 2100s). Both of the boxes had two 9 track drives with the 500cps paper tape readers, and the Facit 75 cps punches. I dont' remember much about the line printer, but there must have been one, probably one of those mini Dataproducts goodies (80 columns). They were configured to use RTE-C, the core image version of RTE used at the time. Thankfully they had 32k of memory, since the RTE stuff took up quite a bit of room, and the machines didn't have disk drives. I ended up writing a memory resident version of the papertape system (I forget what it was called) that would allow assignments of input and output devices to tape files and the like. I heard that it was useful since they had to develop the programs used in RTE-C that way. The application for the machines was for weather observation at the station. The UC Davis people had some nifty humidity sensors (heated, etc.) they were trying out. The other thing we installed was a transmitting weather station (to a satellite that orbited about once every 2 hours). Of course we didn't know when it passed by so the logic (no microprocessors then) spit out the data about once every couple of minutes. The Satellite was in polar orbit so it came by every time. It waqs run from a couple of power sources, an RTG (big huge thing) and a propane thermoelectric generator. I have fond memories of attempting to start the propane thing and not getting the gas to vaporize. I had to use TWO propane torches (one to heat the other) to get it working. Yes, this is classic stuff. It dates to 1975, long before I saw a 6800. __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com

17 years, 5 months

2
1
0 0

Hans destroys VAX!

by evan＠snarc.net

This was brought to my attention at the VCF X. http://www.youtube.com/watch?v=mYP-F7XxrDA For those who don't know him, Han is in the blue shirt and black pants ... his standard uniform.

17 years, 5 months

5
6
0 0

Stats on the first known HP Computer at the South Pole

by ethan.dicks＠usap.gov

Jay, other HP fans, I finally got a chance to re-examine the article on the wall down here. Someone hung up excerpts from "The Antarctic Journal", December 1976, page 286 (and parts of some presumably nearby pages). The article describes the "first" computer system at the Pole, which might possibly be true. During the 1974/1975 Austral Summer, UC Davis sent down a pair of HP 2100S machines to Pole. They were both equipped with 32K of memory, and sported paper tape, at least one line printer, and a pair of 45 ips, 800 bpi magtapes. Other I/O equipment mentioned in the article include an HP 12930A "universal interface", at least one HP 2570A "coupler controller", and at least one HP 12770A serial interface. If I run across the original journal, I can see about making scans. Right now, there is a hodgepodge of xeroxed page fragments taped to the wall. Before anyone starts drooling, this gear was all long-gone 20 years after it was installed. Even the microVAX that was here 10 years ago was packed up and removed years ago. Closest thing I've seen to a "classic" computer I've seen in use here lately was a Dell 386SX/16 as the head-end for the PBX we tore out in 2004, and the Compaq 386N we used for RTTY (last fired up in 2004 as well). It's all modern, boring stuff here now. :-( (except for the classic goodies I pack in my luggage ;-) -ethan -- Ethan Dicks, A-333-S Current South Pole Weather at 6-Nov-2007 at 09:30 Z South Pole Station PSC 468 Box 400 Temp -24.5 F (-31.4 C) Windchill -53.8 F (-47.6 C) APO AP 96598 Wind 16.8 kts Grid 10 Barometer 684.4 mb (10463 ft) Ethan.Dicks at usap.gov http://penguincentral.com/penguincentral.html

17 years, 5 months

4
4
0 0

Quadram Quadboard

by geoffr＠zipcon.net

Does anyone have docs for this beastie? it's an apple-II on a card that goes into an XT... or does anyone have any interest in it? it's been sitting on my shelf for ~ 12 years now...

17 years, 5 months

8
8
0 0

8" disk drive project - maybe 3.5" project too???

by ajp166＠bellatlantic.net

> >Subject: Re: 8" disk drive project - maybe 3.5" project too??? > From: Grant Stockly <grant at stockly.com> > Date: Mon, 05 Nov 2007 22:50:45 -0900 > To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> > >I'm going to add some to my own topic. The questions below still >stand, but I've got more info! : ) > >>I want to use a QUME 842 or SA800 in an altair disk subsystem. >> >>Both seem to have the same interface. >> >>The FD400-5x0-5x1 manual seems to show the drives being quite similar. >> >>The first thing I see is that there are extra signals. >> >>"Trim Erase", "Write Enable", and "Write Data" where the Shugart >>interface only has "Write Data" and "Write Gate". I assume that >>gate and enable are the same thing. The FD Pertec drives also have >>"IN", "OUT", and "STEP" instead of "STEP" and "DIRECTION", but that >>is not a big deal. That can be generated in software. >> >>What I don't see is any input to perform the function of head >>current. How does the shugart interface handle this? >> >>Can I ignore the trim erase feature? How do I generate a write busy >>signal? I'm willing to make some circuits to fake these signals if required. > >More info: > >The pinout of an Altair disk drive...of the wires connected. Omitted >pins are either not connected, power, or ground. All lettered >connections are ground. > >6 - Output - Door Open (IDOP >7 - Head Current Switch (IHCS) >8 - External Trim Erase (Option) (IEEN) >9 - Input - Write Enable (IWEN) >10 - Input - Write Data Input (IWDA) >11 - Input - Step In (ISTI) >15 - Input - Step Out (ISTO) >16 - Input - Head Load (IHLD) >17 - Output - Index (IINXP) >18 - Input - Drive Motor On (IDEN) >19 - Track 0 (ITRK0) >20 - Output - Read Data Output (IRDA) > >One thing that interests me slightly more is the possibility of a >regular 3.5" disk connected to the Altair. I don't care about the >encoding or format being compatible with a standard controller. > >It is very similar, but is also a soft sector disk/drive. How close >is close? Can I just use a microcontroller with a timer to time from >one index to the next and divide it up into 32 sectors? Will this be >close enough for the Altair? Anyone know what kinds of errors I >would get? A microcontroller running at 16MHz would be able to count >between pulses with 16MHz/1 accuracy. With the SA800 I would have a >sector hole sensor giving me the correct timing. > >There still is the issue of the write trim erase feature, whatever that is... Write trim erase is a signal to the head assembly (driver) that turns on the erase segment of the head for erasing the area either side of the head. It's also called tunnel erase. This gives some tolerence to off track reading as the intertrack gaps are "clean". Tunnel erase is still part of all floppy drives but is activated by Write-enable and you never "hear" of it. In 1976 all this was new and magical until Sugart came out with the much simplified 5.25 SA400. >Any comments or ideas on the idea? Is it worth trying? I've got a >very weird tarbell card that formats and uses 3.5" disks as a 70k >mini floppy. I guess anything is possible. : ) Sounds like a wither the DD or SD tarbel card that could interface to most any drive using soft sector. Myself I'd persue something using a 5.25 or 3.5" drive with a current softsector interface to the drive and enough CPU smarts to fake looking like the Altair interface which was dumb as a rock and depended on the 8080 to do most everything. Allison > >2 - Density Select (/REDWC) >8 - Index (/INDEX) >10 - Motor Enable Drive 0 (/MOTEA) >12 - Drive Select 1 (/DRVSA) >14 - Drive Select 0 (/DRVSB) >16 - Motor Enable Drive 1 (/MOTEB) >18 - Direction Select (/DIR) >20 - Head Step (/STEP) >22 - Write Data (/WDATE) >24 - Floppy Write Enable (/WGATE) >26 - Track 00 (/TRK0) >28 - Write Protect (/WPT) >30 - Read Data (/RDATA) >32 - Head Select (/SIDE1) >34 - Disk Change/Ready (/DISKCHG) > >I'm not going to sleep a wink tonight. I hate having ideas at 10PM... : ( > >Grant

17 years, 5 months

2
1
0 0

8" disk drive project

by grant＠stockly.com

I want to use a QUME 842 or SA800 in an altair disk subsystem. Both seem to have the same interface. The FD400-5x0-5x1 manual seems to show the drives being quite similar. The first thing I see is that there are extra signals. "Trim Erase", "Write Enable", and "Write Data" where the Shugart interface only has "Write Data" and "Write Gate". I assume that gate and enable are the same thing. The FD Pertec drives also have "IN", "OUT", and "STEP" instead of "STEP" and "DIRECTION", but that is not a big deal. That can be generated in software. What I don't see is any input to perform the function of head current. How does the shugart interface handle this? Can I ignore the trim erase feature? How do I generate a write busy signal? I'm willing to make some circuits to fake these signals if required. Thanks, Grant

17 years, 5 months

3
3
0 0

2025

2024

2023

2022

2021

2020

2019

2018

2017

2016

2015

2014

2013

2012

2011

2010

2009

2008

2007

2006

2005

2004

2003

2002

2001

2000

1999

1998

1997

test-drb November 2007