test-drb March 2000

test-drb@ccmp.vtda.org

150 participants
515 discussions

AXP vs VAX (was Re: Aaaaahhhh... 'Tis Good to be Back!!!)

by ethan_dicks＠yahoo.com

--- "Zane H. Healy" <healyzh(a)aracnet.com> wrote: > Good Grief! The most any Alpha on my home cluster has is 112MB and my best > Alpha only has 96MB because the RAM is so blasted expensive! I've found > that a Alpha with 80MB is about the same as a VAX with 16MB, and don't even > consider DECwindows in less than 80MB (and you won't see good performance > till 112MB). Ow... that's scary. I am in the process of _finally_ building up this AXP133 "no-name" board I bought a few years ago. Currently, it has 64Mb because parity 16Mb SIMMs are stunningly expensive. I lucked out at the Dayton Computerfest a couple of weeks ago and cleaned a vendor out at $15 per stick. Now my Alpha has 64Mb, my LX will have 64Mb and even my main SPARC-IPX. It's been a memorable experience. ;-) The Alpha has on it an older version of NetBSD. I'm considering upping it to the latest rev or going to RedHat. At the moment, I can't seem to get the 3C509 working, but I'd rather use something a little more advanced like a Tulip-based 10/100 NIC or even a 3C905C (since we have them around the office). One other piece of fun with this "no-name" board was locating compatible cache RAM. I stripped several 486s before I found a set of chips that would let the Alpha come up. The manual mentions a list of preferred vendors. Believe it. -ethan ===== Even though my old e-mail address is no longer going to vanish, please note my new public address: erd(a)iname.com The original webpage address is still going away. The permanent home is: http://penguincentral.com/ See http://ohio.voyager.net/ for details. __________________________________________________ Do You Yahoo!? Talk to your friends online with Yahoo! Messenger. http://im.yahoo.com

24 years, 4 months

Are you sure the 6550 is dead? (was: Mos Technology RAM wanted)

by Philip.Belben＠powertech.co.uk

> I was never a service tech, but here in Ohio, the _only_ static PETs I've > ever seen were 6550-based. I didn't know there were any with 2114s until > I joined this list. It explains another Tramiel story. When the VIC-20 > was being designed, Jack told his engineers that he didn't care how much > memory the new computer used, but it had better take the 2114 chips that > C= had a warehouse full of. Never heard that story before. PETs up to and including 8096 used a couple or more of 2114s for video RAM, though. >> The old PETs don't AFAIK have the internal expansion connector - they have an >> edge connector sticking out at one side. Very useful for toggling RESET with >> a pair of tweezers! > > Don't miss! If I've got to the point where I need to hit RESET, it doesn't matter. Occasionally I corrupted I/O registers and disabled the interrupts that serviced the keyboard. You'd better not miss when toggling IRQ with the tweezers! Philip. ********************************************************************** This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error please notify the system manager. This footnote also confirms that this email message has been swept for the presence of computer viruses. Power Technology Centre, Ratcliffe-on-Soar, Nottingham, NG11 0EE, UK Tel: +44 (0)115 936 2000 http://www.powertech.co.uk **********************************************************************

24 years, 4 months

Are you sure the 6550 is dead? (was: Mos Technology RAM wanted)

by ethan_dicks＠yahoo.com

--- Philip.Belben(a)powertech.co.uk wrote: > > > > > > Yes, I'm sure that's true. The 2114 PETs are rarer, but I can't see any > > If you used to service the things, I have to take your word for it, but I've > seen several with 2114s and I don't think I've seen any with 6550s. Oh well. I was never a service tech, but here in Ohio, the _only_ static PETs I've ever seen were 6550-based. I didn't know there were any with 2114s until I joined this list. It explains another Tramiel story. When the VIC-20 was being designed, Jack told his engineers that he didn't care how much memory the new computer used, but it had better take the 2114 chips that C= had a warehouse full of. > The old PETs don't AFAIK have the internal expansion connector - they have an > edge connector sticking out at one side. Very useful for toggling RESET with > a pair of tweezers! Don't miss! -ethan ===== Even though my old e-mail address is no longer going to vanish, please note my new public address: erd(a)iname.com The original webpage address is still going away. The permanent home is: http://penguincentral.com/ See http://ohio.voyager.net/ for details. __________________________________________________ Do You Yahoo!? Talk to your friends online with Yahoo! Messenger. http://im.yahoo.com

24 years, 4 months

need help reading a paper tape....

by acierno＠mindspring.com

Is there anyone out there who can help me. I have a paper tape (for the KIM-1) and I need it read. I dont care too much what format I get back - disk, paper print out, ect. would all be fine. I thought I had arranged to have it read by a commercial classic computer support person --- but they now tell me that it will be quite some time before they can get to my request. The tape has real historical value ( although not much real $$ value) and I would like to get it read as soon as possible. If you can help me or know of someone who can -- please e-mail me. thank you mark acierno ------- ICQ 40439199 http://www2.msstate.edu/~mja2

24 years, 4 months

IBM 5150, am I nuts or what?

by ethan_dicks＠yahoo.com

--- Bob Stek <bobstek(a)ix.netcom.com> wrote: > For all the pissing and moaning today about IBM and Microsoft, let's face > it - the original IBM and then the XT are collectibles... > What can you do with them? Does the term "boat anchor" have any meaning for > you? I have a 5150 that is serving in its original capacity as a user-interface for a Northwest Instruments bus analyzer box. The analyzer has a 68000 pod and captures the last 4096 bus accesses. I used it once to prove to our engineer that his 68010 design on our VAXBI COMBOARD(R) was screwing up byte accesses (he swapped UDS and LDS causing byte reads to pick up whatever happened to be the last upper or lower byte through the buffers - writes worked perfectly because the 680x0 writes the same data to D0-D7 as D8-D15 on a byte access). The 5150 itself came with an IBM-badged Epson something-X-80 printer, an original mono card (the monitor is long since dead) and some form of multi-expansion card (not an AST six-pack, but something like it). It also has some form of 10-20Mb hard disk in it. I realize this isn't how IBM shipped them, but it is how Northwest Instruments did. ISTR the price paid way back when was $5K for the PC and $20K for the analyzer, but the analyzer price _might_ have included the PC. We boxed the whole thing up at work in a gutted VAX-11/725 cabinet. At one point, we used 11/730s as production machines (linking binaries for our product under a non-primary version of VMS) and it was cheaper to buy 11/725s and harvest parts than it was to buy individual boards for the 11/730 (and a lot cheaper than DEC maintenance). I don't have my working 11/725 anymore, but it was a fun machine when I had it. With a bit of boot tape optimization, it came up almost as fast as our 11/750. -ethan ===== Even though my old e-mail address is no longer going to vanish, please note my new public address: erd(a)iname.com The original webpage address is still going away. The permanent home is: http://penguincentral.com/ See http://ohio.voyager.net/ for details. __________________________________________________ Do You Yahoo!? Talk to your friends online with Yahoo! Messenger. http://im.yahoo.com

24 years, 4 months

Are you sure the 6550 is dead? (was: Mos Technology RAM wanted)

by Philip.Belben＠powertech.co.uk

> Yes, I'm sure that's true. The 2114 PETs are rarer, but I can't see any If you used to service the things, I have to take your word for it, but I've seen several with 2114s and I don't think I've seen any with 6550s. Oh well. [...] > Oh, I did that to check that it was definitely the RAM and not anything > else, long before I posted my request. I could fix about anything else on OK, so you are sure that it is the chip that's dead. I still think it's a fault that affects the whole chip... > The PET determines the RAM size by reading and writing a byte in every > block and assumes it has found the top of RAM when it gets an error. It > was just coincidence that one of the 5th pair was the one to go. So I now > have a 7K PET, because I put the faulty IC in the top pair. It reports > 6143 bytes free. I'm afraid I have a minor quibble here. To write a byte to every block would be pointless as a memory diagnostic, although it would indeed find the top of RAM. However, the PET actually writes two test patterns to EVERY BYTE. PETs I've seen with dodgy RAM come up with really strange numbers of bytes free, not just multiples of 256 minus 1. Early PETS like yours (and my first one) leave 36 in each location when they've finished. Goodness knows why. Later PETS seem to be using 01010101 and 10101010 as test patterns, since they leave 170 (decimal) in each location. (As an aside: vintage PET users, on old machines at least, will have come across the corrupted links in the program listing, which instead of pointing to the next line point somewhere silly. The most common crash then is a program listing that just prints $ signs and doesn't respond to the stop key... Can't remember what keyword 170 gives you on the newer machines, though. When I was involved in developing an adventure game for the BBC micro, we typed a lot of the text on an 8032 (can't remember why). 170 ended up as the token for "HA" when we compressed it. Result - a corrupted address made the machine laugh at us. No, this was not intentional!) ********** Expansion box. The old PETs don't AFAIK have the internal expansion connector - they have an edge connector sticking out at one side. Very useful for toggling RESET with a pair of tweezers! That aside, on this edge connector are brought out most of the block select lines from the 74154 I mentioned in my previous post. In particular, brought out are lines 1 to 7, 9, A and B. It takes only three four-input AND gates to re-encode any eight of these you choose into three upper address lines for a 62256. On my PET I used 2 to 7, 9 and A, and got 32K main memory (including the 8K it already had) plus 8K of RAM in ROM space, above the screen memory. My suggestion is: disable the select to the upper 4K of memory within your PET, and encode lines 1 to 7 and 9. This will give you 32K of main memory, several spare 6550s, and 4K of RAM above the screen. Essentially, you will have a 4K PET fully expanded. Power, as always, comes from the second cassette port... Note block select 0 is NOT present on the expansion connector, so you can't readily disable all the internal RAM. Philip. ********************************************************************** This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error please notify the system manager. This footnote also confirms that this email message has been swept for the presence of computer viruses. Power Technology Centre, Ratcliffe-on-Soar, Nottingham, NG11 0EE, UK Tel: +44 (0)115 936 2000 http://www.powertech.co.uk **********************************************************************

24 years, 4 months

IBM 5150, am I nuts or what?

by SUPRDAVE＠aol.com

In a message dated 3/22/00 4:40:10 AM Eastern Standard Time, mikeford(a)socal.rr.com writes: > I now have a few IBM 5150 Personal Computers, latching on to the nicest > ones today along with I think the correct original keyboards. I have to > wonder if I am not perhaps getting a little dotty in my old age. What the > heck am I going to do with them? > > Anybody else have some? What can they do? > > How about a 5100 (sounded like something I might want to hoard if I see one)? > ive had a 5150 apparently unused in its box for about 2 years now. perfect condition and even has the cardboard shipping disks in its drives! didnt get the documentation though. just recently i found a 5160 in its box as well. its a later model with half height floppy drive. it does have a few cards installed, but machine is extremely clean and no dusty insides. i assume it was purchased as a spare and seldom used, if it ever was. i also have that original pc keyboard with its crappy layout still in its box. DB Young ICQ: 29427634 view the computers of yesteryear at http://members.aol.com/suprdave/classiccmp/museum.htm --You can lead a whore to Vassar, but you can't make her think--

24 years, 4 months

Are you sure the 6550 is dead? (was: Mos Technology RAM wanted)

by pete＠dunnington.u-net.com

On Mar 21, 21:48, Tony Duell wrote: > > else, long before I posted my request. I could fix about anything else on > > the PET, but I draw the line at grinding the top off to poke at individual > > flip-flops in an IC :-) FWIW, the first job I had in > > Really, kids these days..... Well, I once ripped the metal lids off a few ceramic DRAMs to use them as optical image sensors (ISTR an article in BYTE, I think it was, years ago about that), and there's a story about how Ferranti designers determined that a particular ULA design worked perfectly if only you could get at the gates with a microprobe to add a pullup in a certain place, but these SRAMs are plastic and I've run out of fuming nitric acid :-( -- Pete Peter Turnbull Dept. of Computer Science University of York

24 years, 4 months

Are you sure the 6550 is dead? (was: Mos Technology RAM wanted)

by pete＠dunnington.u-net.com

On Mar 21, 23:04, Allison J Parent wrote: > If I knew pinout I could find an industry part that would work save for > pinout or package. No offence, but if I can't get a drop-in replacement, I'd rather leave the original as-is, and build my little expansion board. The idea was to disable internal RAM (and perhaps ROM) and put a decoder on the expansion connector (the old PETs have an internal expansion connector). The expansion would carry up to 32K RAM, and one or more EPROMs holding different versions of BASIC (the original doesn't work properly with IEEE-488 disks and some other devices). Anyway, here's the pinout: MCS6550 1024 x 4 SRAM A0 1 22 Vss (0V) A1 2 21 CS1 A2 3 20 CS2 A3 4 19 ~CS3 A4 5 18 ~CS4 A5 6 17 Vdd (+5V) phi2 7 16 D3 A6 8 15 D2 A7 9 14 D1 A8 10 13 D0 A9 11 12 R/~W -- Pete Peter Turnbull Dept. of Computer Science University of York

24 years, 4 months

Almost free 2-port and 4-port fanouts, IEEE 802.3 compliant, Ethernet Version 1.0 and 2.0 compatible AUIs

by ethan_dicks＠yahoo.com

--- Bill Dawson <whdawson(a)mlynk.com> wrote: > Hello again, > > Well, due to the overwhelming response for these 2-port and 4-port Ehernet > fanouts (actually, none) I'm posting this one more time. Interesting devices if you need one, and quite inexpensive. > Perhaps someone can tell me, on list, why no one on this list has any > interest in these. Maybe everyone is saving their money for iOpeners d8^) I have plenty of vintage networking equipment, but I also have plenty of 10BaseT and 10Base2 transceivers to bring them onto my network. Eventually, I'd like to have a single segment of 10Base5 cable, but just for the antiquity factor. I only have one vampire tap at the moment (on a transceiver that has interchangable media connectors - I have two bases and one actual tap). It's not critical, so as I spot really ancient Ethernet stuff I grab it, but items that are _that_ old don't float by as often as they used to. -ethan ===== Even though my old e-mail address is no longer going to vanish, please note my new public address: erd(a)iname.com The original webpage address is still going away. The permanent home is: http://penguincentral.com/ See http://ohio.voyager.net/ for details. __________________________________________________ Do You Yahoo!? Talk to your friends online with Yahoo! Messenger. http://im.yahoo.com

24 years, 4 months

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test-drb March 2000