U5569462@ucsvc.ucs.unimelb.edu.au (DAVID CLUNIE) (05/26/90)
2 questions/comments: - I am a relative newcomer to this newsgroup and have figured out that the pc532 appears to be a single board 532 design that is available as a printed circuit board. Would it be possible for the designers or distributors of this board to regularly post a "commonly asked questions" type message that would save the net from multiple questions like those that I am about to ask, such as waht are its specs, where does one get it, how much does it cost, and has Unix been ported to it yet ? - I gather that the board has multiple serial lines, buit no video driver. I would love to configure one of these as a "workstation' type thing, but of course one needs a frame buffer to plug into the board. Are there any plans for such a thing ? Surely designing a memory mapped, 24-bit, no graphics processor, uses dynamic RAM, frame buffer would be pretty easy compared to designing the CPU board ! At least 1240 by 1192 driving a multisync monitor, with lesser resolution as an option (to driver cheaper lower frequency monitors), possibly with an 8-bit mode with a 24-bit palette for those with lesser needs or who can't afford the memory. I could live without a graphics processor and that would certainly make the design simpler, but could everyone else ? Is dual-port RAM worth the cost (circa 4 times I think) ? I would have thought that most of this could be acheived with off-the-shelf components, though I doubt if I am up to doing it myself. I am sure someone in this group would be able to though, and the result would be a real Sun killer once Unix is going ! Regards ... David
george@wombat.UUCP (George Scolaro) (05/26/90)
In article <740@ucsvc.ucs.unimelb.edu.au> U5569462@ucsvc.ucs.unimelb.edu.au (DAVID CLUNIE) writes: >2 questions/comments: > > - I am a relative newcomer to this newsgroup and have figured out that the >pc532 appears to be a single board 532 design that is available as a printed >circuit board. Would it be possible for the designers or distributors of this >board to regularly post a "commonly asked questions" type message that would >Unix been ported to it yet ? Not yet. The two camps are AT&T Sys V and UCB 4.2. There is active interest but of course source + licensing issues are still in progress, stay tuned. ------- The PC532 is a homebrew NS32532 based motherboard. It was designed during a 2 year period, evolving from a PC/AT wirewrap prototype to a baby PC/AT sized motherboard. The complete schematics (gerber files if required) and PLD equations for the design are freely available, as is all the source code that has currently been written. The initial 'production' run of PCBs came to 65, and a further 37 have been mostly shipped (2 to go). With National Semiconductor's generous support we were able to supply 50 NS32532, NS32381 and NS32202 chipsets with the first 50 PCB orders. The initial 65 boards were kitted with the more hard to get components and connectors. Kits with NS chipset were $450 and kits without were $400. The current run of PCBs will not be kitted (by us) but S. Ligett, who is on the mailing list is arranging a similar volume purchase of components. In addition to the PC532 there are several add-on boards being actively designed, with some already complete. They include: - Host SCSI adapter for the PC/AT to be used in conjunction with the PC532. This board is currently a wirewrap design. - Floppy disk and centronics adapter, plugs into the PC532, uses SCSI to communicate with the PC532 (or any other SCSI based master). There are at least two designs in progress. - Various medium/high resolution graphics display adapters. - An i860 based board. - Ethernet + 16 serial port adapter. NS32GX32 20MHz on board CPU. Plugs into the PC532 and communicates via SCSI. May also be run standalone. Designed but waiting for photoplotting and fab (I'm going on holidays in a month, so will wait till my return - 1st week of August). The main justification for the PC532 and its brethren is 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. Over the past few years there has much discussion in some of the news groups about designing the ultimate homebrew computer, but this rarely ever concluded. The reality is that few people actually have enough spare time to design and carry through to completion anything other than the simplest of projects. 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. The current PC532 mailing list has a mixture of people with hardware and software backgrounds. It currently appears that the software people outnumber the hardware people. This is probably a good thing, since it ensures that any hardware that is produced will have good software support, based on the infinite number of monkeys principle (or less than infinite if some aren't monkeys :-) ). Following is a partial excerpt from the PC532 Functional Description document: 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 board currently runs a modified version of MON16 which enables a 32000 host system to download code, set break points, source level debug etc. Bruce Culbertson has also ported his monitor to the PC532 and is in the process of porting Minix. His Minix port has already been running for considerable time on his home brew 32016 based computer. Compute performance is roughly 10 X a 32016 based system (ICM3216). I/O performance should be considerably faster. Total of 50 devices, including CPU etc, but excluding the DRAM SIMMs. There are 2 D-speed PAL devices and 3 B-speed PAL/GAL devices on the board. All glue logic, buffers and latches are either 74AS or 74ALS technology. The PCB is 6 layers, 13.5 inch x 8 inch baby AT form factor. It connects to a standard AT power supply (draws 2.6 Amps typical), has holes to mount in an AT chassis, has 4 XT (mechanical only) slots that will accept XT or AT wirewrap prototype cards (power pins are XT compatible). > - I gather that the board has multiple serial lines, buit no video driver. I >would love to configure one of these as a "workstation' type thing, but of >course one needs a frame buffer to plug into the board. Are there any plans >for such a thing ? Surely designing a memory mapped, 24-bit, no graphics > stuff deleted... >Regards ... David Well, the area of graphics support certainly created much discussion, some excited (heated?), with the end result being a few people deciding to go their own way. This of course is fine, as long as we standardize on the software interface (the hardware interface is easy - scsi) then we can choose whichever board we want (and can afford!). Note 1: This project is purely non-profit, homebrew, not affiliated with any company etc. etc. By having a relatively large group of people with similar interests, group buys can be arranged (with the good faith of all concerned) for better component pricing. Note 2: All the current PCB's are spoken for except for 2. Once they are gone, we will have to wait for another group of people to indicate interest etc, the more we get made in one shot, the cheaper they are. The last batch of 37 were US$200 each + shipping (including documentation). best regards, -- George Scolaro george@wombat.bungi.com [37 20 51 N / 122 03 07 W]