Eureka!

[...] Sure. I have the Installation/Service manual for the 98032, which gives much the same info (and a full schematic of the interface). The 98032 had several 'options', though. The basic model was for custom applications and had a back shell with an unterminated cable (which you had to wire to the appropriate connector(s) for your applications), and no jumpers installed. The 'options' were for specific HP peripherals. I believe that the 9866 printer, one of the disk drives, the 9877 cartridge tape unit, a badged Facit 4070 paper tape punch, etc were all connected to the 9825 via a correctly configured 98032 interface. The 'option' consisted of having the right connector correctly wired to the cable and having the right jumpers factory-installed to set the interface up correctly. Alas the manual I have does not give any info on how the 'options' were wired. Yes I could probably work it out in most cases, but it would be nice to know the official way to do it. Here's an example, from the only 'option' I have -- for the 9885 disk drive: DD50 Wire 98032 Signal 1 9 A25 Drain 2 905 A1 Gnd 3 906 B1 Gnd 4 927 A22 Ctl0 5 902 A21 PReset 6 928 A23 Ctl1 7 918 B21 EIR 8 9 A18 Gnd 9 9 B18 Drain 10 98 A19 Pctl 11 903 A24 Gnd 12 904 B24 Gnd 13 8 B19 Pflg 14 908 B20 Psts 15 901 A20 I/O 16 916 B22 Sti0 17 917 B23 Sti1 18 948 A2 DO15 19 947 A3 DO14 20 946 A4 DO13 21 945 A5 DO12 22 937 A6 DO11 23 936 A7 DO10 24 935 A8 DO9 25 934 A9 DO8 26 97 A10 DO7 27 96 A11 DO6 28 95 A12 D05 29 94 A13 DO4 30 93 A14 DO3 31 92 A15 DO2 32 91 A16 DO1 33 90 A17 DO0 34 N/C 35 926 B2 DI15 36 925 B3 DI14 37 924 B4 DI13 38 923 B5 DI12 39 915 B6 DI11 40 914 B7 DI10 41 913 B8 DI9 42 912 B9 DI8 43 7 B10 DI7 44 6 B11 DI6 45 5 B12 DI5 46 4 B13 DI4 47 3 B14 DI3 48 2 B15 DI2 49 1 B16 DI1 50 0 B17 DI0 Jumpers : 2 Output +ve true 7 DMA Enable 8 Clock high input byte on rdy B Word Input E Clock low input byte on rdy F Word Output THe 9877 has a 50 pin Blue Ribbon connector on the back. I know what the signals on that are, and can make a guess at how to wire them to a 98032. I can also make a guess as to what jumpers to fit. But if anyone has the right option it would save that guess work. -tony