Apple III
Computers in Collection
General Info
RAM
TODO: 12V vs. 5V TODO: 12V RAM bizarre IC-on-dip packages TODO: System RAM diagnostic TODO: My RAM stack hack. Where’d those pictures I took go?!
Power Supply
C1: “250V~MP fo=3,0MHz”, “PME 271 M 622”, “Rifa GPF 40/085/56”, “0,22uF”: “Metallized paper cap 0.22uF 250VAC 068-22400010”. According to Digi-Key/datasheet: 20.3mm lead spacing, 24mm x 16.5mm x 11.3mm. Holes on PCB are 15mm or 20mm spacing.
http://www.kemet.com/Lists/Filestore/EvoxRifaRFIandSMD.pdf suggests Kemet PHE840M family is a substitution for PME271M. Try Kemet PHE840MB6220KB12R17 or PHE840MD6220KD13R06L2.
Parts values and characteristics were also checked against “Astec_Power_Supplies_Aug82.pdf”
Apple III, serial A3S1-021975
Inventory
Case
| Attribute | Value |
|---|---|
| Manufacturer | Apple |
| Model | A3S1 |
| Serial | A3S1-021975 |
| Source | 2019/Aug/17, craig@OMSI |
Logic Board
| Attribute | Value |
|---|---|
| Manufacturer | Apple |
| Part | 820-0043-00 |
| Serial | TODO: |
| Markings | “APPLE COMPUTER” “820-0043-00” |
| Source | 2019/Aug/17, craig@OMSI |
RAM Board
| Attribute | Value |
|---|---|
| Manufacturer | Apple |
| Part | 820-0021-01 |
| Serial | TODO: |
| Markings | “APPLE III MAIN MEMORY CARD” “APPLE 1980 820-0021-01” “610-_-” “MADE IN U.S.A.” |
| RAM Voltages | includes 12V |
| ICs | 16 x Mostek MK4332D-3, 32 x TMS4116-20NL (“8118” “8122”), 1 x ITT 4116 3N “8128” |
| IC sockets | all RAM chips |
| Source | 2019/Aug/17, craig@OMSI |
RAM rows B and C are 18-pin sockets, which presumably accept 32Kbit chips (like the Mostek MK4332 module-ICs) and 16bit chips if placed so that socket pins 9 and 10 are open.
Power Supply
| Attribute | Value |
|---|---|
| Manufacturer | Astec |
| Model | AA11190 |
| Serial | 19007983 (hand-written) |
| Date Code | “8035” |
| Markings | “02015203” “Made in Hong Kong” |
| Source | 2019/Aug/17, craig@OMSI |
External Floppy Drive
| Attribute | Value |
|---|---|
| Manufacturer | Apple |
| Model | A3M0004 |
| Serial | A3M0004-00492 |
| Source | 2019/Aug/17, craig@OMSI |
CRT Monitor
| Attribute | Value |
|---|---|
| Name | Apple Monitor III |
| Brand | Apple |
| Model | A3M0039 |
| Serial | B2K 158852 |
| Manufacture Date | November 1982 |
| Manufactured In | Japan |
| Manufactured By | Hitachi |
| Source | 2019/Dec/21, Hayden@Craigslist |
Maintenance Log
+5V supply voltage is reasonably correct and safe.
No video output and no floppy-busy LED, but motherboard LED lights.
20190801
Rifa capacitor (C1?) popped. TODO: Replaced? With which part number?
20190902
(TODO: Is this logic IC testing?)
Tested OK: B[10,12,13], D[2,3,4,5,6,7,8,9,11,12,13], E[2,3,7,8,9,10,12,13], F[2,3,10,11,12,13], G[2,3,6,7,10,11,12], H[7,8,9,10,11,12], J[4,6,7,8,9,10,11,12], K[3,7,8,9,12] Untested: B[1,4,6,7,9,11], C[2,9], D[10], E[4,5,11], F[5,7,9], G[4,9], H[3,4,6,13], J[2,3], K[1,10,11]
TODO: Document the RAM repair!
Finally back to working! This is an Apple demo for the Apple III’s high-resolution graphics.
Documentation
TODO: List documentation? Or is that far too fiddly?