ftpam1@acad3.fai.alaska.edu (MUNTS PHILLIP A) (08/26/90)
I don't normally watch this news group but I noticed quite a bit of new posting about the PC532. Could someone tell me what it is, and what software is available for it? How hardware dependant is the software? Many eons ago, (1984/1985) I built a small system using the NS32008. My cross-assembler ran on a CP/M machine! Nowadays I think in terms of nodes on a LAN rather than full standalone systems. Is it reasonable to port the PC532 software to a board with no more I/O than a LAN port?
george@wombat.UUCP (George Scolaro) (08/27/90)
In article <1990Aug26.061711.8591@hayes.fai.alaska.edu> ftpam1@acad3.fai.alaska.edu writes: > > I don't normally watch this news group but I noticed quite a bit >of new posting about the PC532. Could someone tell me what it is, and what >software is available for it? How hardware dependant is the software? Many >eons ago, (1984/1985) I built a small system using the NS32008. My >cross-assembler ran on a CP/M machine! Nowadays I think in terms of nodes on >a LAN rather than full standalone systems. Is it reasonable to port the PC532 >software to a board with no more I/O than a LAN port? The PC532 is a National Semiconductor 32532 based home-brew computer. It was designed over a period of 1 year starting in April 1988. The critical portions were prototyped on a wirewrap board to verify the design and evaluate the performance. Many changes to the design were made as memory prices were dropping and new devices were appearing. When the design stabilized, the task of laying out the printed circuit board commenced. Needless to say, more changes occurred requiring re-routing of entire sections. June 1989 saw the first prototype run of 5 boards. Due mostly to the meticulous care (it was our money) that went into the design and layout of the board, there was only one cut and jumper on the board to take care of a design error. That error has confirmed that you should never believe all that application engineers tell you. The PC532 was intended to replace two old and obsolete home UNIX systems, both based on National Semiconductor microprocessors. These systems use the NS32016, 32 bit devices that have somewhat less than 1 MIP performance. In comparison the the NS32532 at 25 MHz executes around 10 MIPS. The performance difference has been verified by various benchmarks including compilations or large source code files. The main justification for designing the PC532 was to foster free hardware design and to provide a platform for development of freely available software. With the evolution of the PC/XT/AT computers, hardware hacking has been on the decline. In addition, the increasing complexity of new generation CPUs has also made it difficult for the home based tinkerer to venture into the design of a computer system. The PC532 attempts to provide the base from which new designs can gain leverage. In the long term the PC532 will likely become an adapter for a higher performance CPU. The PC532 is a motherboard which mechanically fits into a PC/AT case. The mounting holes and power supply connections are arranged accordingly. The PC532 has 4 PC/XT slots which are mechanically placed to enable a PC/AT case to be used, though electrically they support the SCSI protocol. The printed circuit board (PCB) has 6 layers, comprising of two active outer layers, 2 active inner layers, 1 power layer and 1 ground layer. The PC532 board has the following features: 1 x NS32532 25 Mhz CPU 1 x NS32381 25 Mhz FPU 1 x NS32202 10 Mhz ICU 1 x DP8490 SCSI device that manages a 62 pin XT mechanically compatible 4 slot multi-master bus. This bus can run to at least 3.8 megabytes per second. Multi-master is supported by the DP8490 SCSI device. 1 x AIC6250 SCSI device, connects to a 50 pin SCSI header. This device is intended to connect to hard disk and mag tape media. The AIC6250 supports async and sync SCSI. The interface supports data transfer rates over 4 megabytes per second. 4 x SCN2681 DUARTs. This gives the PC532 8 serial channels, which are all individually connected to interrupt inputs on the ICU. Each DUART generates an INT and in addition a wire or-ed RX ready channel A/channel B. 1 x 27256 EPROM (200 ns). This EPROM contains any necessary boot firmware. It is intended that a Dallas Semiconductor (or compatible) clock chip/socket be used under the EPROM to give the PC532 a battery backed real time clock. 4/8 megabytes (1 megabit x 8/9 80ns SIMMs) or 16/32 megabytes (4 megabit x 8/9 80 ns SIMMs). Page mode dram devices must be used and the design utilizes the page mode access to achieve 0 wait state read (1st access), 0 wait state write, 1 wait state for the rest of a read burst if in page. If not in page a penalty of 4 wait states for reads and 3 wait states for writes occurs. The result is a peak 50 megabyte/second memory interface (while bursting in page). The design contains a total of 50 devices, including CPU etc, but excluding the DRAM SIMMs. There are 2 D-speed PLD devices and 3 B-speed PLD devices on the board. All glue logic, buffers and latches are either 74AS or 74ALS technology. During the design and development period we saw several discussions on the UNIX News network by groups that were trying to design a similar home-brew system. None of these groups ever produced a design due to the large number of conflicting opinions. We had the advantage of being a smaller group. The PC532 was architected by two people, one hardware oriented the other software oriented. Even with only two people, many discussions (battles) occurred (were fought) prior to the final specification and design. We quietly went our own way and designed and produced working boards. After several months of testing we were confident that the design was solid. We then posted to the network that we had a working home-brew design and that we would gladly supply the schematics, PLD equations and the photoplot data base for the cost of postage. A month or so of discussions occurred during which several people indicated that they would be interested in purchasing blank printed circuit boards. We then began the task of getting quotes from several board houses and posting them to the network. As more people ordered boards, the price continued to drop and so on. Finally we had 65 boards being fabricated with more people indicating that a second run would be viable. We have just completed a further 37 boards and indications are that a third run is likely in a few months. The success of the PC532 is partly due to the generosity of National Semiconductor, which supplied 50 sets of NS32532/NS32381/NS32202 and DP8490 devices enabling us to offer a very low kit price for the first 50 boards we shipped. The UNIX News network is the rest of the success story, it provided a mechanism to communicate with people having similar interests throughout the world. The PC532 proved that it is still possible to construct a system with state of the art devices in a home environment. The software used was all PC/AT based and the equipment included a 100MHz oscilloscope and the normal set of soldering and wirewrapping tools. At this stage, Bruce Culbertson has ported Minix to the PC532. Software includes various revs of the GNU C compiler and several assembler/linkers. The collection of software and hardware is beginning to grow as more owners complete the construction of their boards. There are around 30 or so PC532s running at this stage (that are known about). best regards, -- George Scolaro george@wombat.bungi.com [37 20 51 N / 122 03 07 W]
dc@max.berkeley.edu (Dave Cottingham) (08/30/90)
In article <1163@wombat.UUCP>, george@wombat.UUCP (George Scolaro) writes: >At this stage, Bruce Culbertson has ported Minix to the PC532. Software >includes various revs of the GNU C compiler and several assembler/linkers. I just started reading this list yesterday. I have never heard of Minix before. Could anyone (Bruce Culbertson for example) tell me a little about it, like how to get my hands on it? Thanks, Dave Cottingham dc@max.berkeley.edu
rhyde@ucrmath.ucr.edu (randy hyde) (09/02/90)
So how does someone order one of these boards and what do they cost? Indeed, how much does the whole kit cost? *** Randy Hyde O-)
culberts@hpccc.HP.COM (Bruce Culbertson) (09/05/90)
Re: What is Minix? Every month there is lengthy Minix info message posted to comp.os.minix. It was just posted in the last day or two so if you access to that group, take a look. Otherwise, I would be happy to forward it. In a nut shell, Minix is: a Unix V7 look-almost-alike; moving towards POSIX within a year or two; copyrighted and sold by Prentice-Hall; less than $100 (last I looked) for the OS, libraries, most familiar Unix utilities, compiler, and all sources except for the compiler; and runs on an IBM-PC or Amiga ST. I ported Minix to the pc532, which was described in this news group very recently. Bruce Culbertson