stacey@guug.de (05/17/91)
ET532 BOARD COSTS - An initial low quantity, high unit cost PCB fabrication run, cross subsidising a following higher volume much cheaper run seems unattractive. - Rebating 1st run participants from a 2nd run would help, but be complex. - I suggest we all (ie 1st & 2nd runners) subscribe to a high volume cheaper pcb run. (Have faith - The PC532 is testimony to George Scolaro's PCB design skill !) `2nd Run'ers could minimise cash risk & further expenditure, by delaying buying chips until they hear George confirms his board works &/or issues a `Cut & Rewire' PCB minor surgery list! WIRE WRAP - George, have you done a wire wrap prototype, or are WW propagation problems repellent &/or assembly time considered unattractive/unnecessary ? (Ethernet software testing/development could be tried on a WW board). - I bought a blank prototyping WW board (~50 DM (= ~$US 30)) that inserts in my PC532 (gold plated edges, 13.2" * (3.9" + 0.3"), (125 + 4) hole * (36 + 1) hole; (CONN 15 has plenty of room for pin tails). I hope to use it for low quantity wire wrap designs, &/or prototyping. ADDING PROTOTYPING AREAS ON `SLOT IN BOARD' UNUSED SPACE - We only have 4 slots, let's conserve them, & squeeze as much functionality on each PCB as possible, even if not everyone fully populates each PCB. - Once we have a design ready to fabricate cards with, spare unused areas could be laid out as prototype areas with matrix holes for solder / wire wrapping. The extra cost of the prototyping matrix area holes will be minimal. - The scsi bus might also be presented to that area, to allow prototypes to separately interface to scsi, avoiding prejudicing/complicating the existing `slot in' board design by attempting shared bus access (however enough space would have to be available for separate cpu,scsi ctrl, etc). MOUNTING HOLES ON `SLOT IN BOARDS' - Let's put mounting screw holes (~6 ?) on each card, to allow alternate later mounting in non PC/AT form factor boxes. One day we may want to transfer our scsi/whatever controller cards to another machine. (Holes in the wrong place for an as yet unknown future box will be more usable, with a bit of extra metalwork, than no holes at all). Julian (stacey@guug.de)