The latter covers the issue 2 and 3 spectrums and is related to the board layout diagrams available here and here. One for the case assembly and another for the board assembly. Parts lists for the zx spectrum are provided in table form.
Upper ram is limited to texas instruments ti4532 but oki 3732 can be used with a minor modifcation. It also has provision for the full 48k of ram on the main pcb. This followed the issue 1 quite quickly in august of 1982 and was the first spectrum issue to be laid out using cad tools.
Issue 1 boards have several defects which are corrected via factory modifications. Fd 1 floppy disc drive. C48 cassette header include.
Zx spectrum 2a 3 schematic redrawn by guesser for 3 delete. Ear 2 mic 98 nmtr 33 ndwr 36 ndrd 35 strb 47 busy 1 prnt 34 vcc2 91 vcc1 41 gnd1 15 gnd2 40 gnd3 66 gnd4 90 ic1 11 vcc. Component layout template of the issue 2 spectrum circuit board issue 3 board schematics.
Schematic diagram of the issue 2 spectrum circuit board issue 2 component layout. Issue 2 board schematics. Schematics component layouts and port connector pin outs.
Zx spectrum technical section. 1 2 ic15e reset 1 strobe 2 d0 3 d1 4 d2 5 d3 6 d4 7 d5 8 d6 9 d7 10 nc 11 busy 12 nc 13 nc 14 gnd 15 nc 16 gnd 17 nc 19 gnd 20 gnd 21 gnd 22 gnd 23 gnd 24 gnd 25 gnd 26 gnd 27 nc 28 gnd 29 nc 30 nc 31 nc 32 nc 33 gnd 34 nc 35 nc printer connector upper lower 0v 3 4 ic15f 330pf c53 0v expansion connector upper zx spectrum 2b schematic for 2b. The zx spectrum 2b issue 2 motherboard pdf file.
Making them eqivalent to the issue 2 motherboard.
Zx spectrum issue 2 schematic. Zx spectrum pcb schematics and layout. Here you ll find schematic and layout information for various models of the zx spectrum. Issue 1 schematics and layout pdf. 128 issue 6u analogue and digital side schematics 2 z70500 issue 3 power section and main pcb schematics.
The zx spectrum 2b issue 1 motherboard pdf file. Re draw revision 17 updated 2020 01 23. This schematic describes the circuit of a 2b with a z70833 issue 1 motherboard. Some boards have factory fitted modifications.
Some boards have factory fitted modifications. This schematic describes the circuit of a 2b with a z70833 issue 1 motherboard. Re draw revision 17 updated 2020 01 23.
The zx spectrum 2b issue 1 motherboard pdf file. 128 issue 6u analogue and digital side schematics 2 z70500 issue 3 power section and main pcb schematics. Issue 1 schematics and layout pdf.
Here you ll find schematic and layout information for various models of the zx spectrum. Zx spectrum pcb schematics and layout.
