IBM PS/2 Model 30-286 - Two ROM Sockets? - Page 1
Forum section: electronics / general

author: Halcyon
author_rank: Unknown
timestamp: May 27, 2015, 08:20:26 am
content: Hi guys,I was hoping someone with a little more working knowledge about the IBM PS/2 range of computers might be able to assist with this one.There are two socketed ROMs on the motherboard. I assume (only based on the age of the machine) that both are for the BIOS; An odd/even pair.I took a ROM dump of each for backup purposes and wondered if I was actually correct. There are no markings on the chips to indicate which is which and nothing printed on the motherboard itself to give any clues as to which might be odd and which might be even, or whether one is for the BIOS and the other is for something completely different.The only thing Google turned up was an old technical document from IBM which indicated that the one marked with P/N 30F9580 is part of the BIOS. According to the ROM dump, seems that the P/N of the other chip is 30F9579.The first few bytes of each ROM are as follows:Chip 1 (with the white label).Code:30F9580 (C) COPYRIGHT IBM CORPORATION 1981, 1988 ALL RIGHTS RESERVED œÀÐúp.q°ÐæëäXÃPÀÐúp.Äq.Øp.qChip 2 (with no label).Code:30F9579 (C) COPYRIGHT IBM CORPORATION 1981, 1988 ALL RIGHTS RESERVED ÐùØæëäP.Øp.Am I looking at an odd/even pair here or something else?

author: Unknown
author_rank: Unknown
timestamp: May 27, 2015, 08:58:11 am
content: From my (very rusty!) memory they were an odd-even pair, at least in early versions.This listfrom the MAME folks seems to agree.

author: helius
author_rank: Super Contributor
timestamp: May 27, 2015, 08:59:04 am
content: With consecutive FRU numbers it's very likely they form a pair, especially if they are the same logical size.Also given that the 286 uses a 16-bit data bus.G***le foundhttp://www-05.ibm.com/services/ecalib/doc/8550-039.txtdescribing 8530s with either two or one ROM chips.

author: VK3DRB
author_rank: Super Contributor
timestamp: May 27, 2015, 11:37:58 am
content: A bit of info you might find quite interesting...I was involved in the initial introduction of the PS/2 model 30 in late 1986. Code name was Palace. Considering you are in Australia, it most likely originated from our IBM plant in Wangaratta. It was the first of the PS/2 models, followed shortly by the model 50 and the model 80. That machine cost a fortune in its day, but it was well designed. I seem to recall there were two BIOS chips... I think they were odd/even addresses. I used to have the entire source code listing to the BIOS and Advanced Diagnostics on my PC at work, which I used to hack to make tests from. It would not surprise me your machine still functions. Prime spec parts were used throughout and the SMPS's were extremely robust. You will find the RAM is ECC.The amount of testing per machine leaves what is done today for dead. You motherboard underwent a 12 hour dynamic burn-in test from about 5 deg C to 65 deg C, then it was functionally tested on a FACT tester imported from Boca Raton in Florida. (I now own that FACT test machine. The machine originally cost $350,000. I bought it for $100 and stripped it down make a nice ESD bench with built in power supplies.) As an assembled PC, your machine underwent further extensive testing. Less than 1% valid warranty claims were received.The Palace motherboard was most likely the first surface mount PCB to be made in Australia, because we installed Australia's first SMT plant initially for the PS/2 family. If it were made in Wang, I could tell you the names of assembly and test people who put your machine together, and the names of the engineers involved. When the Palace was made, the Wangaratta plant had only about 90 full time personnel... a great place to work where we were like one big family. At its peak 10 years later there were the equivalent of 600 full time hires and we had the biggest electronics plant in the country by far. We made a few MILLION PCs there for all of Australasia and some of EU and the USA. The reason I moved to Wangaratta for the great opportunity to be at the forefront of technology and get to travel around the world. We had a ball, and in those days money was no object in getting things done. But in 1998, IBM cashed in by selling us off to a shonky startup which ceased business about 2 years later, leaving in its wake a path of social, electronic and economic desolation in Wangaratta.A little known fact is that we also manufactured a very large volume of Apple Power MAC processors. My job was developing the hardware and software for the testing them. Because of the Power MAC and the IBM RISC systems, in 1995 we were the biggest exporter of non-primary produce in Australia.Times have certainly changed. It is all gone. Except maybe for your machine, my FACT tester desk, and a plethora of HP and Tektronix test equipment scattered about Australia.

author: helius
author_rank: Super Contributor
timestamp: May 27, 2015, 05:54:47 pm
content: Cool story, thanks.I've noticed that IBM used more proprietary package technologies than other vendors. Notably, metal can PGA and the blue translucent QFP that were on those PowerPCs.

author: Halcyon
author_rank: Unknown
timestamp: May 27, 2015, 08:01:24 pm
content: VK3DRB, thank you for that awesome story. This is the stuff I love hearing about.Indeed this machine was made in Wangaratta and still works perfectly. The original 20MB hard disk has some 30 bytes of bad sectors on it, but that's about it. It was nice of IBM to think ahead and socket the Dallas RTC module. Of course by now the original battery had died resulting in none of the CMOS settings being kept, but I just swapped it out with a brand new Dallas 12887+ from Element14 and it works perfectly.The other thing I liked about this model is that it used 16 bit ISA slots and not that MCA stuff. Makes life easier these days.I'll take a few photos and post on here this week when I get a moment.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: May 28, 2015, 02:47:44 am
content: Curious........so, if they are interleaved (which does seem likely), why are the headers notCode:3300FF99558709 ((CC)) CCOOPPYYRRIIGGHHTT IIBBMM ...??! Or, they precisely *are*?'Cuz surely if those headers are in the address space (it would be quite wasteful or complicated to do otherwise?), well...Other thought, was an outside shot: ROM BASIC. I don't remember when that was dropped though.Hmm, I have an XT compatible with dual ROMs (and RAMs, since, 8086 16 bit local bus FTW!), wonder how those read individually. I don't recall any strings (at precisely F0000 or otherwise) showing up weird though. I don't have a ROM reader handy to look, either.Tim

author: VK3DRB
author_rank: Super Contributor
timestamp: May 28, 2015, 01:45:31 pm
content: There were two 27C512's in the machine, containing BIOS. The chips shared the 16 address lines. One supplied the lowest 8 bits of data, the other the highest 8 bits of data (ie: odd/even byte arrangement). Many of the chips on that board and others from the era were from VLSI Logic. I have no idea what happened to VLSI Logic, but they were a key vendor to IBM for a few years.HERE IS THE SCHEMATIC TO THE MACHINE...http://www.dasarodesigns.com/schematics-and-resources/?drawer=files*IBMIBM never supplied BASIC in PROM on any of their machines, except on the old 5100, 5110 and 5120 minicomputers (which I also worked on). For PC's, BASIC was always supplied on diskettes or cassette.Another fact about IBM boards is they never had NiCad batteries in them. It was against company policy to design anything with them in due to the cadmium environmental pollution. Most clones however had NiCad cells in them.

author: Alkemyst
author_rank: Newbie
timestamp: May 28, 2015, 07:44:57 pm
content: Hi,I received a text about this thread from my brother. I used to support (some say I actually created, but it existed in part already) the IBM PS/2 FAQ on USENET starting around 1992 and later WWW.I have high confidence that those two chips are a BIOS pair for that machine. The second should have had a similar label, but these tend to fall off over time.Here is a diagram of that board from an old friend of mine:http://ps-2.kev009.com/ohlandl/8530/8530-286_Planar.htmlYour chips are ZM11 and ZM12, 30F9580 BIOS Even and 30F9579 BIOS Odd; respectively.Here are various versions which may be helpful for things and possibly put you in touch with websites that can be more helpful/have kept current:Version 4.0:http://www.computercraft.com/docs/ps21.shtmlVersion 5.2:http://ibm-pc.org/manuals/ibm/ps2/ps2-faq.txtVersion 5.4:http://www.computercraft.com/docs/ps2faq54.shtmlVersion 5.5:http://ps2page.tripod.com/ps2faq.txt(this site has reference disks, diagnostic disks, etc for PS/2 models mostly the 85, 90, and 95's)Version 6.0 Final:http://www.30moons.com/ps2faq.php(my personal site)This site is more complete for disks:http://ibm-pc.org/diagnostic/ibm/ps2/ps2files/index.htmand has the starter and advanced diagnostic disks for the Model 30 and 30-286, the main site is worth a look toohttp://ibm-pc.orglots of drivers and the like:http://www.members.aon.at/mcabase/index.htmThe models prior to "50" I didn't really focus too much on as they were really standard 80x86 boxes running ISA architecture as opposed to the MCA architecture of the models 50 and up. I helped many people understand what reference discs were and how to make their dead machines come back to life. I was running my Model 95 (with a 486DX50 at 150MHz and later an AMD 5x86 at 150MHz)) as late as 2003 prior to moving to a Celeron 300A and back to convention ISA/PCI and later AGP/PCI-E machinesA lot of the PS/2 Reference material is extremely hard to find on Lenovo, they had absorbed all of IBM's documentation back in the day and it was readily available underwww.lenovo.com/psref/now that resolves to psref.lenovo.com and it's not very good for old PS/2's. This was one document I found:http://www.lenovo.com/psref/pdf/ps2book.pdfExpect to find broken links and the like above as some of this sites have not been updated in years.Cool to see these machines still ticking. In the post-heyday they found their way to many places overseas and I would get calls praising my PS/2 FAQ...it's the only computers they could get in many financially challenged areas.Hope this helps and I didn't run on too much.Å

author: Halcyon
author_rank: Unknown
timestamp: May 29, 2015, 02:59:36 am
content: Alkemyst, thank you for joining the forum and adding to the discussion. Your contribution is very much appreciated. Since the search engines also crawl this forum, there are probably many people who aren't members who can now benefit for everybody's input.Cheers!PS(2): I love the layout of your site -- the old green screen -- simple yet effective!

author: retiredcaps
author_rank: Super Contributor
timestamp: May 29, 2015, 05:44:36 am
content: Quote from: VK3DRB on May 27, 2015, 11:37:58 amInteresting story. Thanks for sharing.

author: Halcyon
author_rank: Unknown
timestamp: May 29, 2015, 08:06:56 am
content: Just for those who enjoy old "DOS porn", I'm currently running SpinRite on the IBM PS/2 (with 20MB hard disk) to give it a good workout and prepare for a new operating system. See crude screen shots below.This is going to take a while...(More photos coming soon, once I put it all back together.)

author: SeanB
author_rank: Super Contributor
timestamp: May 29, 2015, 07:19:42 pm
content: NDD V4 looks remarkably similar..... IIRC Steve Gibson intimated that the internals were actually a copy of his assembler code, with some fudging of the exe to remove the names and replace them in the file.

author: VK3DRB
author_rank: Super Contributor
timestamp: May 30, 2015, 12:14:56 am
content: Quote from: Halcyon on May 29, 2015, 08:06:56 amI cannot see anything pornographic in your images, but I guess everyone to his own. Maybe you were addicted to Leisure Suit Larry.

author: Halcyon
author_rank: Unknown
timestamp: May 30, 2015, 05:32:57 am
content: Quote from: VK3DRB on May 30, 2015, 12:14:56 amHah, well thatdoesput a new meaning to 'DOS porn'. I think I have all the LSL disk images somewhere (including the new Leisure Suit Larry Reloaded made a few years ago).