Sequential Circuits Prophet-5 Service Manual - Audiofanzine

SECTION 13PROPHET-5 REV 3.3 UPDATEThis modification increases the Prophet-5*s program storage capacity from ^0 to 120.The update involves adding a jumper to the back of PCB 2 Left Control Panel, addingRAM and some logic to the Rev 3.2 PCB 3 Computer Board, and changing thesoftware. The Update Kit (#Z-205) includes the following parts:PARTSCM1000C.2Prophet-5 Rev 3.3 Op Manual Addendum1-043 6116 RAM1-240 74C00 Quad NAND gate:i-01724-pin DIP socketZ-994 Prophet-5 softwareZ-068 Prophet"5 120-Factory Program CassettePROCEDURE1. Switch power off and disconnect the Prophet from the AC line.2. Open the box. (For instructions, see Section 1 of Technical Manual TMIOOOD.)3. Disconnect and remove PCB 4.4. Disconnect and remove PCB 3.5. See Fig. 1 and add the jumpers shown to the back of PCB 2. This ties together thedisplay decimal points (pins 4 and 9) to LD7, pin 33 of TB201, as shown on the Rev 3.3PCB 2 schematic (attached).6. The remaining modifications to PCB 3 are illustrated in Figs. 2 and 3, and the Rev3.3 PCB 3 schematic (attached). First bend out all the pins of the enclosed 74C00 QuadNAND gate, except pins 4, 7, and 14. Solder this device "piggyback" to U309 (74C02)at pins 4, 7, and 14 (Note that U309 is oriented with pin 1at the upper right).7. The added 74C00 is designated U387. Jumper U387 pins 2, 1, 14, and 13 in a looparound the end of the IC.8. Jumper U387-10 and U387-11.9. Jumper U387-4 to U387-9.10. Jumper from the feed-through for U311-1 (All), to U387-5 and -12. It should bepossible to do this with one piece of wire.TM1016A 4/8213-1