test-drb

test-drb@ccmp.vtda.org

101090 discussions

stepping machanism of Apple Disk ][ drive (was Re: Heatkit 51/4 floppies)

by allisonp＠world.std.com

<Z-80, which was enjoying almost universal acceptance as the most widely <applicable and easiest-to-use microprocessor available. Most of the popula I could argue it was or it wasnt. ;) Keep in mind at that time I was doing 8048, 8085, z80, 1802, 6100, sc/mp, TI9900, LSI-11, some 6502 and 6800. That does not include the uCOM4 (NEC 4bit) and uCOM75 (cmos high end 4bit) parts. <statements about it were pretty much on the money. Of course, the evolutio <of the 64K DRAM made its refresh counter more or less useless, but the Only some as a goodly portion still had 128 address row refresh (NEC4164 and About four others). But 64kDrams were really a year out due to price in late 79 being rather high. (then design cycles for new products wer 9-18 months too). <the Apple to accomplish the same thing. Meanwhile, Motorola was making a <BIG mistake, abandoning the amateur and "small" users. Yes! The 6800 if you had the 25$ big book you were an expert if you could read. Later parts did come so cheaply supported. <Since the evolution of the now-popular 'C' and PASCAL compilers for the <8051-core micro's, I believe the popularity of this 25-year-old model has <actually increased. The HLL's and the development of high-speed versions o Yes it has but the code it not as dense as hand written. Then again with the availability of LARGE ROMs/EPROM/EEPROM it may be development timeover code density. <'51-core user. I believe that it's as a consequence of that, that there ar <now compilers for several truly "ugly" architectures, e.g. the PIC/SCENIX Yes they were never a favorite for me but then again I could program them as they looked like the 4bitters I used to work with. <class of processors. There are also VHDL and VERILOG cores for several of <the older architectures, e.g. 650x, available for those who prefer to <"roll-their-own" which are also, though less well, supported with compiler <and other tools. If your need embedded 8051, 6502 and z80 are good choices. <Again, Motorola seems to have been left behind at least with their smaller <MCU's. I guess that's because of their reputation for spurning application <which consume fewer than 100K parts per week. Yep, seen that before. Now the worst thing I've seen was the 8086/8 and its heirs. I really hated writing code for it. The segmentation scheme was one horrid hack. Allison

26 years, 8 months

stepping machanism of Apple Disk ][ drive (was Re: Heatkit 51/4 floppies)

by allisonp＠world.std.com

<> The point was apparently missed. Of course I can take a cmos z80 and <blow <> that out of the water using a 6 or 8 mhz clock. < <But because of the way the phases are used, a 2MHz 6502/65C02 is running a <roughly the same rate (for comparable operations) as a 4MHz Z80. Yes, the 6502 overlaps the instuction fetch and execute (mini pipeline). The z80 is more classic multi-state machine. In the end the two parts are roughly the same speed for their generation. IE: a 4mhz z80 does basic operations in 1uS and 6502 at 2mhz is about the same. the difference is any is when complex indexing or other tassks are discussed where the z80 has a better instuction set (though slower...more states) the 6502 uses more small instructions(fast but many). In the end they do the same task just different. That supports the only logical conclusion... clock speeds dont count. The full measure is instruction execution time. Which is why I used the PDP-8 example as that machine used 1.4uS core yet it had a fairly high effective speed. Now to extend this to other older cpus there are some out there that were just plain slow or due to their instruction set so awkward as to end up being slow. Allison

26 years, 8 months

Parting out PDP-8a

by mbg＠world.std.com

>I would also like to lay my hands on a programmer's console. It's one of >the only things (besides hex-high core) that I'm missing. Same here... the 8/A I recently got seems pretty fully loaded (I haven't yet itemized what's in it), but the one thing it doesn't have, and that I really really want is a programmer's console for it... Megan Gentry Former RT-11 Developer +--------------------------------+-------------------------------------+ | Megan Gentry, EMT/B, PP-ASEL | Internet (work): gentry!zk3.dec.com | | Unix Support Engineering Group | (home): mbg!world.std.com | | Compaq Computer Corporation | addresses need '@' in place of '!' | | 110 Spitbrook Rd. ZK03-2/T43 | URL: http://world.std.com/~mbg/ | | Nashua, NH 03062 | "pdp-11 programmer - some assembler | | (603) 884 1055 | required." - mbg | +--------------------------------+-------------------------------------+

26 years, 8 months

Parting out PDP-8a

by ethan_dicks＠yahoo.com

--- jeff.kaneko(a)juno.com wrote: > Guys: > > I have discovered a PDP-8a in a scrapyard near my workplace. > It has been outside for awhile; but if there are any salvable > parts there, would anyone be interested? But of course. > BTW-- How do I get the front panel off without breaking > anything? Depending on the front panel style, if you see two 1/4" holes, one on either edge, it may take an allen wrench. If the panel has no apparent tool access, it's probably held in place by a pair of ball and socket joints on each side which can get extremely tight if pressed on too hard and left to sit. There are times when I think I'm about to bust the balls right off the backplace, and sometimes I'm right. :-( What's inside? What are you offering? At this point, I could even use a new chassis as I have a full set of a mix of verified working and untested boards (128kW MOS, RL8A, etc). I'm sure that the memory and disk I/O work; I am not certain that my spare DKC8AA is any good. ISTR that about 10 years ago I pulled it and set it aside for acting up. I would also like to lay my hands on a programmer's console. It's one of the only things (besides hex-high core) that I'm missing. -ethan _________________________________________________________ Do You Yahoo!? Get your free @yahoo.com address at http://mail.yahoo.com

26 years, 8 months

PDP-8/E PSU Debugging (was Q-bus pinout)

by CLASSICCMP＠trailing-edge.com

>>> There should be >>>some plastic catches (or more likely the remains of same) on the PSU. > >>I've found that most half-inch tape seals have latches which are >>quite amenable to being used as replacements for the original plastic >>catches :-). >Tim, >I think I'm going to have to plead ignorant here. What are "half-inch tape >seals"? You know those 2400-foot, 600-foot, and other lengths of half-inch tape that are used in 7-track and 9-track drives? The reels are commonly enclosed in plastic straps with latches; the strap with the latch is the "tape seal". I think "Tape Seal" may actually be a trademark of Wright Line. The latch part usually has a plastic hook extending >from it that you can hang the tape up by on a Wright Line tape stand or cabinet. There are non-Wright-Line tape seals with very different plastic designs that serve the same general purpose, but are specifically designed for auto-loading tape drives. These seem to be more common in IBM shops. -- Tim Shoppa Email: shoppa(a)trailing-edge.com Trailing Edge Technology WWW: http://www.trailing-edge.com/ 7328 Bradley Blvd Voice: 301-767-5917 Bethesda, MD, USA 20817 Fax: 301-767-5927

26 years, 8 months

What if,... early PCs (was: stepping machanism

by edick＠idcomm.com

You've got two tracks mixed up, I think. True, the Apple II was quite plentiful in 80, but not in businesses the way it was in 82-83. I even had several of them with people to man them as well. I hated the Apple but loved the 6502. In the meantime, I noted that the RS Model 1 was a piece of junk, and, in fact, so much of one that I never bought one, even for experimentation, and I had nearly every other sort of box around the shop. The Model 3 design my employer had contracted to him was paid for in late '81. I saw several of them in friends' houses, none of whom had bought them new, by the way, so they'd been on the market for a time in '82-83. We had a really terrible blizzard on Christmas of '82 here, and I saw one in a neighbor's house then. It was an early version but it was a model 3. I'm aware there were plenty of Apples around since the one which was wheeled in to the weekly 6502 Users' Group meeting by the chief guru was not even attracting a second glance. A lot happened in the early part of '81, i.e. Apple prices dropped for the first time, in an effort to retain market share >from the now increasingly available though not yet particularly attractive, either as a computer or as a budget item. There's some more imbedded commentary below, if you're interested. Dick -----Original Message----- From: Allison J Parent <allisonp(a)world.std.com> To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> Date: Saturday, April 10, 1999 5:59 PM Subject: Re: What if,... early PCs (was: stepping machanism ><The IBM entry into the PC market was in mid-1981, I think, and the Model-3 ><was rushed to get out ahead of it. The Apple-II exlposion wasn't quite ><underway yet, but the handwriting was on the wall. > >No. By then the apple and trs80 were common as house flies. In fact in >1980 we used Apples and TRS80s running a similar program for forcasting >as they were in wide use around the shop. They were both in the market >in terms of volumes nearing a 500k system each if not more by 1980. The model 1 was quite common, but the model 1 was in too many pieces to be of much interest to most folks. What's more, it was pretty weak-kneed. The model 3 held out hope, though that was later dashed when the model 3 turned out to be not much better. >the PC wasn't an impact until 82 maybe 83. Memories and events seem to >get compressed or expanded. I's even say the PC was not a serious >contender till mid 83. The initial impact of the PC was to get people to stop buying non-PC's for their businesses. They were extremely costly at first, and didn't have a few serious problems worked out. People had to mortgage their houses to buy one (a basic PC on the gray-market cost nearly $2k). >Allison >

26 years, 8 months

OT: copying OS/2 Warp

by max82＠surfree.com

Hi, I managed to borrow a hard drive with OS/2 warp on it from someone. I want to copy it onto my own drive. How do I do this? I know that in DOS, I would do a sys command to make the drive bootable. There is no sys command here. What should I do? --Max Eskin (max82(a)surfree.com)

26 years, 8 months

stepping machanism of Apple Disk ][ drive (was Re: Heatkit 51/4 floppies)

by pete＠dunnington.u-net.com

On Apr 11, 10:20, Richard Erlacher wrote: > Subject: Re: stepping machanism of Apple Disk ][ drive (was Re: Heatkit 51 > I have to disagree with your comparison of the 2 MHz 6502 with a 4 MHz > Z-80A. My thought here is that the 4MHz Z-80 used in the conventional way, > had a memory cycle of 750 nanoseconds (3 clock ticks), while the 6502, at > whatever rate, again, used in the conventional way, had a memory cycle of > one clock tick. Now, some instructions involve several memory cycles, but > that was true of both processor families. What I often cursed, was that the > textbook application of the 650x core left memory available (idle) half the > time. That was a blessing up to a point (2.5 MHz to be exact) because it > allowed for DRAM "RAS-precharge." The Apple and others like it proved that > at around 1 MHz, the 6502's memory could be used for an entirely separate > purpose, e.g. video refresh. I wasn't talking about precisely 2MHz vs 4MHz, just a ballpark figure (as opposed to "about the same" or "about ten times" clock speeds). So, given the rest of your message, I think we're in broad agreement. BTW, BBC Micros have a 2MHz clock on the 6502, and interleaved video and processor access quite happily in 1980. The video took care of the refresh requirement. > I believe there are entirely too many subjective, architecture-related, > factors to allow an absolute comparison/contrast of the two processors. Agreed :-) That's why lies, damned lies, and benchmarks are so much fun :-) > In my "gut" I still believe the 4 MHz Z-80 is about > comparable to a 1.5 MHz 6502. Well, that's not very far from what I wrote, is it? I was just pointing out that although Allison seemed to imply that a 6 or 8MHz Z80 was much faster than a 4MHz(? I haven't got the original message any more) 6502, I believe that to be far from the case. -- Pete Peter Turnbull Dept. of Computer Science University of York

26 years, 8 months

PICK OS

by max82＠surfree.com

I saw an interesting book at the library today about something called PICK OS. I didn't get to look through the entire book, but I read enough to see that it refers to directories as dictionaries. It seems to take a novel approach, but I know nothing about it. Haven't even heard of it. Does anyone here know more? Does anyone here have the PC version (mentioned in the book)? --Max Eskin (max82(a)surfree.com)

26 years, 8 months

stepping machanism of Apple Disk ][ drive (was Re: Heatkit 51/4 floppies)

by edick＠idcomm.com

I have to disagree with your comparison of the 2 MHz 6502 with a 4 MHz Z-80A. My thought here is that the 4MHz Z-80 used in the conventional way, had a memory cycle of 750 nanoseconds (3 clock ticks), while the 6502, at whatever rate, again, used in the conventional way, had a memory cycle of one clock tick. Now, some instructions involve several memory cycles, but that was true of both processor families. What I often cursed, was that the textbook application of the 650x core left memory available (idle) half the time. That was a blessing up to a point (2.5 MHz to be exact) because it allowed for DRAM "RAS-precharge." The Apple and others like it proved that at around 1 MHz, the 6502's memory could be used for an entirely separate purpose, e.g. video refresh. At one point in time, I went to some lengths to demonstrate the relative performance capability, based on common applications, when the processors were placed in an environment in which the primary constraint on the processor's performance, hardware-wise, was the memory bandwidth. It turned out to be a rather difficult comparison, because of the lengths to which one had to go in order to utilize the memory bandwidth most effectively. The Z-80's most difficult aspect was that its memory cycles were of different lengths. The 6502 could be interfaced quite easily by using an asymmetrical clock, with a short Phase-1 (the period during which addresses and control signals change) and a relatively long Phase-2, which is the cycle when I/O to off-chip system-resources take place. This was straightforward until the system design was adjusted for DRAMs, which were the most common problem of that time. Both processors had problems with DRAM usage. The 6502, when its clock was tweaked to make DRAM access most time-efficient required, absolutely, that a cycle-stealing arrangement was used in order to support refresh. This meant extra hardware. However, the otherwise minimalist Z-80, which once was touted as supporting DRAMs by generating a refresh cycle from time to time, required extra hardware to modify its clock as well in order to allow for a long enough M1 cycle, and to allow enough time for the refresh to occur during its allocated window. This meant even more hardware. It turned out that all the things which the processors' designers had done in order to make the two chips "efficient" became a problem when I tried to implement each one in a way which was tailored to attain the most effective utilization from what was then the most costly system resource, the main memory. In any case, what I determined was that the Z-80, in spite of its complicated hardware requirement, was potentially the faster processor. This was based on a comparison of the two in what I then considered an application tailored to the most effective use of memory bandwidth. I also quickly concluded that the 6502 would outperform it in an application where memory demand was small enough to allow the use of SRAMS, because if the fastest Z-80 available at the time (1981) was handed memories fast enough to operate it at full speed with no wait-states, i.e. minimal hardware, the M1 cycle was still so short as to use the normal Phase-1 time of a 4 MHz 6502, the memory cycle of which was a single clock tick as opposed to the Z-80's three. I believe there are entirely too many subjective, architecture-related, factors to allow an absolute comparison/contrast of the two processors. Being mostly a hardware-oriented type, I find the analysis adequate to warrant the second conclusion above, though I've never been entirely satisfied with the comparison I made based on their relative speed in the execution of a BASIC program. The BASIC interpreters were different, and the programs had to be "fiddled-with" in order to make them both run. The difference was not overwhelming, so I've never been entirely comfortable with the concusion. In my "gut" I still believe the 4 MHz Z-80 is about comparable to a 1.5 MHz 6502. Back in 1980, the Z-80 was definitely the wisest choice if you had to settle on a single processor for carrying out useful business tasks, because the Z-80 could run CP/M which had LOTS of such "useful" programs, thoroughly debugged, most of which were entirely suitable for commercial use, and there were significantly fewer useful-work programs for the 6502, which was more popular in graphics-oriented systems because it could share its memory and because its instruction set was apparently better suited for moving icons around in a display memory as most game programs required. Dick -----Original Message----- From: Pete Turnbull <pete(a)dunnington.u-net.com> To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> Date: Sunday, April 11, 1999 8:35 AM Subject: Re: stepping machanism of Apple Disk ][ drive (was Re: Heatkit 51/4 floppies) >On Apr 11, 9:16, Allison J Parent wrote: > >> The point was apparently missed. Of course I can take a cmos z80 and >blow >> that out of the water using a 6 or 8 mhz clock. > >But because of the way the phases are used, a 2MHz 6502/65C02 is running at >roughly the same rate (for comparable operations) as a 4MHz Z80. > >-- > >Pete Peter Turnbull > Dept. of Computer Science > University of York

26 years, 8 months

PR1ME 2550 Up and Running

by geoffrob＠stmarks.pp.catholic.edu.au

---------- > From: John Lawson <jpl15(a)netcom.com> > To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> > Subject: PR1ME 2550 Up and Running > Date: Monday, April 12, 1999 10:11 > > > > Well... it didn't hurt as much as I thought it was going to.. > > I have just run "SHUTDN ALL" after two hours of playing with PRIMOS > (on a DEC LA120 running at 300 baud... s-l-o-w...). My first encounter with VMS was on a Vax 6310 using a Decwriter II at 300 baud. :^) > I rescued this system about two months ago, and finally got tired > of it taking up space. Nice work, a Pr1me is on my want list too. Can you post a pic on web site somewhere? > And, apropos of the Pick discussions, this machine has INFORMATION > loaded and running... haven't messed with it yet, tho..

26 years, 8 months

Chicago trs-80s

by steverob＠hotoffice.com

On Tuesday, April 06, 1999 4:24 PM, Mike [SMTP:dogas@leading.net] wrote: > My vacation/computer-rescue-mission has come to a close and there is now a > big honkin pile of trs-80 6000 and 16b toys on my living room floor. :) > Several of them have broken this or thatsz but the first one I pulled, a > 6000hd 15mhd, booted into Xenix 3.0.1 I think (Microsoft '84). the 68k in > it crashed after about 20min of xenix frolicking. She's resting now. I'd > like cc and tcp for this if anyone can help me out? I 'm sure some parts > will be available as soon as I figure out what I have. Software, give me > software or give me death. > > ;) > - Mike: dogas(a)leading.net > Mike, Nice haul... A couple of weeks ago, I got a Model 2 and a Model 16 sans keyboards. Both machines had been in storage for a long time and were absolutely filthy. After careful disassembly, cleaning, and reassembly, the Model 2 returned to life. Another list member has located a keyboard for me (thanks) so, that one is complete. I haven't found a boot disk for it yet but, I'm sure it'll work just fine. Last weekend I opened up the Model 16 to see if it could be resurrected. The hard drive had been previously removed but it looks like everything else is there. After the ritual cleaning, I applied power to the computer and promptly smoked the floppy drive. One of the traces on the PCB lit up like a freakin Christmas tree. DAMN! I'm surprised it didn't blow a fuse or something. I haven't looked at the drive too closely so, I'm not really sure what happened there. If it is a power supply problem, the whole machine could be history. I'm hoping it was a problem with the floppy and didn't kill anything else. I have not been able to get a trace on the CRT and really don't have the enough tools to properly diagnose the problem. I did however notice the filament on the CRT was glowing and the cooling fans were running. I believe the fans get power from the 110AC primary and the filament could be >from an unregulated source. So, this doesn't totally eliminate a Power Supply problem. Can anyone tell me what voltages should appear on the PS connectors? Is there an easy way to determine if the processor is alive? Unfortunately, I don't have a scope or logic probe :-( If anyone can suggest a good source for a Logic Probe, I'll consider buying one? If I'm unable to get this thing working, I'll make the parts available. The case and CRT are in really good condition so, don't trash any of the Model 16 parts yet. Between us, we should be able to put another one together. Good Luck, Steve Robertson - <steverob(a)hotoffice.com>

26 years, 8 months

stepping machanism of Apple Disk ][ drive (was Re: Heatkit 51/4 floppies)

by pete＠dunnington.u-net.com

On Apr 11, 9:16, Allison J Parent wrote: > The point was apparently missed. Of course I can take a cmos z80 and blow > that out of the water using a 6 or 8 mhz clock. But because of the way the phases are used, a 2MHz 6502/65C02 is running at roughly the same rate (for comparable operations) as a 4MHz Z80. -- Pete Peter Turnbull Dept. of Computer Science University of York

26 years, 8 months

Speaking of Tandy & TRS-80 (was: Re: What if,... early PCs

by edick＠idcomm.com

There was another one I haven't seen in a couple of decades, called Allied. I once worked for a subsidiary of another Allied Electronics, so they must have been gone by then. Laffayette was a place where I bought audio components, e.g. speakers, crossover networks, passive radiators, grille-cloth, etc. Of course that was in the '60's . . . When the periodic table was easy to memorize, . . . let's see, there was air, earth . . . Dick -----Original Message----- From: Steve Robertson <steverob(a)hotoffice.com> To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> Date: Saturday, April 10, 1999 9:01 AM Subject: RE: Speaking of Tandy & TRS-80 (was: Re: What if,... early PCs >On Saturday, April 10, 1999 10:16 AM, Charles P. Hobbs >[SMTP:transit@primenet.com] wrote: >> >> >> Does anyone remember a similar electronics store called "Lafayette"? They >> were a big chain, probably not nearly as big as Tandy Radio Shack though; >> I think they went under in 1980 or 1981 > > >I used to visit the Lafayette store in Ft. Lauderdale on a regular basis. >IIRC this was in the Early 70's. The store primarily had audio gear, HAM >equipment, and electronics components. Similar to the Radio Shacks of that >time. > >As a matter of fact, I still have a Lafayette Stereo Amplifier at home. I >used it for about 10 years then it quit working on one channel. Probably a >bad output transister. I just never got around to fixing it... > >I don't recall ever seeing any digital stuff in the stores. Of course this >was VERY early in the micro-processor development stage. > >Steve Robertson - <steverob(a)hotoffice.com> >

26 years, 8 months

Parting out PDP-8a

by jeff.kaneko＠juno.com

Guys: I have discovered a PDP-8a in a scrapyard near my workplace. It has been outside for awhile; but if there are any salvable parts there, would anyone be interested? BTW-- How do I get the front panel off without breaking anything? Jeff ___________________________________________________________________ You don't need to buy Internet access to use free Internet e-mail. Get completely free e-mail from Juno at http://www.juno.com/getjuno.html or call Juno at (800) 654-JUNO [654-5866]

26 years, 8 months

TI99: Re: DAEMON mail

by allisonp＠world.std.com

<I think that what occurred was that a group of list server messages were at Try line breaks...PLEASE! the reso ot that line scrolls around the side of the tube and under the desk. ;) Allison

26 years, 8 months

What if,... early PCs (was: stepping machanism

by allisonp＠world.std.com

< I've got issue 2, Vol 1 of PC World dated Mar 83 .Compaqs Portable Comput <was reviewed in this issue, and the reviewer mentions that IBM had introduc <the PC 1 1/2 years earlier. Thanks for the validation. At 46 Iwas there and am still young enough to not be siffering from alzhimers. That and I have the same mags and adds. ;) Allison

26 years, 8 months

stepping machanism of Apple Disk ][ drive (was Re: Heatkit 51/4 floppies)

by allisonp＠world.std.com

<I believe (guessing because I've learned memory doesn't serve as it once <did) The load is two clock ticks and the indirect, indexed jump is five, s <that's 3.5 microseconds, give or take a tick. it's less at 4 MHz, which i <what the 65C02C is rated, though it readily will run at 4.9152 (24.576 <MHz/5) over a wide temperature and voltage range provided the clock is <phased correctly. the divice-by five yields a 40/60 h/l which must be <inverted to give a little longer phase-2 than phase-1. The point was apparently missed. Of course I can take a cmos z80 and blow that out of the water using a 6 or 8 mhz clock. Heck using a 1989 version of the z80, the Z280 at 12.5mhz I can get the execution time way down. In the time frame before 1982 (as a marker) there werent any 4mhz 650c02s and there were 4mhz z80s and pdp-8s were still produced. In that context the the example represent programming style rather that absolute speed as they didn't vary that much over all to represent a great diffferece unless you needed a characteristic that was specific to a given CPU. I'm not slamming the 6502 or it heirs as it's also a very popular embedded CPU still. For that fact so are the Z8 and Z80 heirs. Just from that it's possible to conclude they all had desirable enough characteristics to keep them in the running. As a CPU the 8051 is ok, I use it. As a controller it's without question a popular part still. But as a general purpose cpu, it's a really bad C or Pascal compiler host/target. Allison

26 years, 8 months

PICK OS

by jolminkh＠nsw.bigpond.net.au

Max Eskin wrote: >I saw an interesting book at the library today about something called PICK >OS. I didn't get to look through the entire book, but I read enough to see >that it refers to directories as dictionaries. It seems to take a novel >approach, but I know nothing about it. Haven't even heard of it. Does >anyone here know more? Does anyone here have the PC version (mentioned in >the book)? > >--Max Eskin (max82(a)surfree.com) > I have never played with PICK, but I have played with Prime "Information" which is sometimes described as a PICK like operating system. I have a PC version somewhere but in that form it is not a true OS. It is started as a DOS application. As someone else has said, not much use except for multi-user database applications. The PC version is only a toy.

26 years, 8 months

Heathkit H-8 again

by bluoval＠mindspring.com

It was a 16 button keypad, with numbers 1-9, decimal point, and math operators and two others I couldn't make out. Could someone tell me what these keys were?

26 years, 8 months

Micropolis 1518 Jumper Settings

by edick＠idcomm.com

There's a pretty slick controller for ISA by Lark Associates which is capable of lying to the PC in a way which actually convinces it you have two physical drives. This makes using such large beasts much easier. I've not been able to get good mileage out of my Miniscribe 9760 or my Maxtor 8760 since it ( the controller ) gave up the ghost. My WD controllers won't help with making it old-bios-compatible. Dick -----Original Message----- From: jpero(a)cgocable.net <jpero(a)cgocable.net> To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> Date: Saturday, April 10, 1999 8:20 PM Subject: Re: Micropolis 1518 Jumper Settings >Date sent: Sat, 10 Apr 1999 20:46:00 -0500 >To: jpero(a)cgocable.net >From: Jeff Kaneko <jeff.pat(a)mindspring.com> >Subject: Micropolis 1518 Jumper Settings > >Hi Jeff and to cc follows: > >> >> Attached is all of the information that I have; I haven't been able to try >> this because I'm stuck without a capable ESDI controller. > >Thanks! But same old hat again, it's same thing you see on the >blue planet's website. > >There are few ESDI controllers that can do 24MHZ and *MUST* >able to do up to 4096 cylinders. Nice thing about all ESDI >controllers for Peecees, LBA built right in for greater than 528MB! > >> Looks like you should set for 512 bytes/sector, 83 spt, *hard* sectored. I >> wish I knew that Ultra 12f-24's were so damned rare . . . > >Really? What about it and why it's bit rare? > >And I really beg to anyone on this list to pool their experiences to >"pull" up the ESDI performance because I'm getting subpar >performance for a "high" end hd like 1538 with 71 sectors (1518 is >83 sectors) both hds should have screamed instead of plodded >along. About 600KPS out of that 1538, yuk. I got over 800kps on >that same controller with a Miniscribe 3180E on that paltry 36 >sectors. > >Is there's a controller card that does much better than this Ultrastor >12F24?! Oh, I've one computer based on EISA. > >Oh, anyone knows of same HDAs that uses SCSI interface board >in place of ESDI, I want to know what model it shares same HDA >for each? 1518 and 1538. > >> >> >> Jeff > >Wizard

26 years, 8 months

stepping machanism of Apple Disk ][ drive (was Re: Heatkit 51/4 floppies)

by edick＠idcomm.com

referring to your questions regarding the execution time > >Execution time for an 8E (1973) would have been under 8uS if both instuction >used indirect addressing. As written it would be 7.6uS. Now the 6502 at >2mhz would have done it in what? > I believe (guessing because I've learned memory doesn't serve as it once did) The load is two clock ticks and the indirect, indexed jump is five, so that's 3.5 microseconds, give or take a tick. it's less at 4 MHz, which is what the 65C02C is rated, though it readily will run at 4.9152 (24.576 MHz/5) over a wide temperature and voltage range provided the clock is phased correctly. the divice-by five yields a 40/60 h/l which must be inverted to give a little longer phase-2 than phase-1. I've imbedded a few comments in the text below. Dick -----Original Message----- From: Allison J Parent <allisonp(a)world.std.com> To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> Date: Saturday, April 10, 1999 5:58 PM Subject: Re: stepping machanism of Apple Disk ][ drive (was Re: Heatkit 51/4 floppies) ><I knew somebody woudl come up with a good example. That 6809 code is ><probably the closest thing I've seen in a micro. The 8051 uses a similar ><approach, pointing to the table with the datapointer and uses the > >The 8051 is very ugly in other places. It has a sufficiently varied instruction set that you don't really have to use what you don't like. Perhaps you can take comfort in the fact that it's been around since the early '80's and is still the most popular architecture out there. What's more, it's not nearly as ugly as the PIC architecture. >Then there are the NEC uPD 78xx series that are similar in register layout >to z80 but code wise, not close. They have a table lookup instructions for >that exact task. They are targetted as rom based controllers and code >efficientcy is a requirement but often controller don't need to preocess >the kinds of things a PC (or other general purpose computer) would. > >The z280 has a load address inscrtuction that makes the setup for an indexed >jump easier. > >The PDP-11 did it on one instuction but it has some very powerful addressing >modes. Indirection and indexing are natural to that part. > >However in CPUs righer in register than the 6502, the task would be done >far differently. It's a different programming style and it does impact >code structure. For example a set of operations that can be done requiring >multiple (say a dozen) 16bit parameters to be passed are easily done on >even 8080 but the 6502 has to do that as indexed list in ram and pass >the pointer to the list if you want to be efficient. It's possible to >structure a problem such that any cpu looks good or bad. Generally an >application is far more than a trivial few instructions. > >Look at the PDP-8 which is both register poor and has an instruction set >that small is far from adaquate to describe. Yet it performs tasks >efficiently in small amounts of core that some cpus can't. > >The 6809 example would be in PDP-8... > > / enter here with uart data > DCA pindex / store index value at pindex > JMP I,INDEX / indirect jump via index (could have been a JMS, jump > / subroutine!) > >Execution time for an 8E (1973) would have been under 8uS if both instuction >used indirect addressing. As written it would be 7.6uS. Now the 6502 at >2mhz would have done it in what? > >< They (DEC) did make the uVax-II as a chipset for interfacing to their ><BI-bus, I believe, so that might qualify as well. The DEC chipset probabl ><didn't sell for what a 6809 costs, even the faster part, and certainly not ><the $0.86 I last saw on the 4MHz Rockwell 65C02. > >?????? UvaxII was not for interfacing the BI, that was a dedicated chipset. >The uVAXII was a single chip (extended FPU and DMA were companions). UvaxII >was only remotely related to BI bus. The statment doesn't parse. > ><I'm not surprised that it was in the 6809 that this instruction came up. ><The 6809 showed lots of promise at first, but once it was in hand, one ><clearly could see that it would be MUCH easier going with the MC68008 if on ><had to use an 8-bit bus. I never had the opportunity to write in a > >the 6809 was a bridge part while waiting for the 68K. Still it was a good >part. I found them both (6809 and 68K) to be a disappointment. I guess there was too much wait, and it wouldn't have mattered what they put out. ><high-level language for the 6809, but I was told it should have been quite ><easy to write a high-quality efficient compiler for it because of its ><repertioire of instructions and addressing modes. I turned out literally > >Nearly as good as the PDP-11. FYI both the 6809 and the 68k had heavy >PDP-11 and vax influences. > > >Allison >

26 years, 8 months

Micropolis 1518 Jumper Settings

by jpero＠cgocable.net

Date sent: Sat, 10 Apr 1999 20:46:00 -0500 To: jpero(a)cgocable.net From: Jeff Kaneko <jeff.pat(a)mindspring.com> Subject: Micropolis 1518 Jumper Settings Hi Jeff and to cc follows: > > Attached is all of the information that I have; I haven't been able to try > this because I'm stuck without a capable ESDI controller. Thanks! But same old hat again, it's same thing you see on the blue planet's website. There are few ESDI controllers that can do 24MHZ and *MUST* able to do up to 4096 cylinders. Nice thing about all ESDI controllers for Peecees, LBA built right in for greater than 528MB! > Looks like you should set for 512 bytes/sector, 83 spt, *hard* sectored. I > wish I knew that Ultra 12f-24's were so damned rare . . . Really? What about it and why it's bit rare? And I really beg to anyone on this list to pool their experiences to "pull" up the ESDI performance because I'm getting subpar performance for a "high" end hd like 1538 with 71 sectors (1518 is 83 sectors) both hds should have screamed instead of plodded along. About 600KPS out of that 1538, yuk. I got over 800kps on that same controller with a Miniscribe 3180E on that paltry 36 sectors. Is there's a controller card that does much better than this Ultrastor 12F24?! Oh, I've one computer based on EISA. Oh, anyone knows of same HDAs that uses SCSI interface board in place of ESDI, I want to know what model it shares same HDA for each? 1518 and 1538. > > > Jeff Wizard

26 years, 8 months

Tutti 0.2a Tomy Tutor emulator relased

by ckaiser＠oa.ptloma.edu

A non-text attachment was scrubbed... Name: not available Type: text Size: 755 bytes Desc: not available Url : http://www.classiccmp.org/pipermail/cctalk/attachments/19990410/82c36d8e/at…

26 years, 8 months

PICK OS

by geoffrob＠stmarks.pp.catholic.edu.au

---------- > From: Max Eskin <max82(a)surfree.com> > To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> > Subject: PICK OS > Date: Sunday, April 11, 1999 6:30 > > I saw an interesting book at the library today about something called PICK > OS. I didn't get to look through the entire book, but I read enough to see > that it refers to directories as dictionaries. IIRC, it is a dedicated O/S for use with a database system. Sort of a bootable database program for want of a better description. I (briefly) owned a Fujitsu computer that had PICK installed, it came out of a public library and was a very solid box, that weighed a LOT. (It had a ups built into it!) Fujitsu bought it off me! True! They were still supporting some in service and wanted some parts, offered me twice what I paid for it. (I rang them to get some info on the machine and they called back an hour later with a cash offer.) Never had more than a cursory look at the O/S, but I gather it's quite good at what it does, but it doesn't do much else. Multi terminal time share system. TV station I used to work for also had a PC based Pick System, the logging program (used to create the "logs" actually a plan of the order and length of programs that re to be put to air) ran on that and nothing else it seems... >It seems to take a novel approach, That's a fair description. It seems to be dedicated to just one task. I think there are other things it can do, but it's fairly limited... That's the limit of my knowledge, others on the list will doubtless know far more... Cheers Geoff Roberts VK5KDR Computer Systems Manager Saint Marks College Port Pirie, South Australia geoffrob(a)stmarks.pp.catholic.edu.au

26 years, 8 months

Jump to page:

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