Sinclair ZX Spectrum 48kB
Sinclair ZX Spectrum +

IM2FIX removes hardware bug that causes screen noise when IM 2 is selected and I register contains value range #40..#7F. The noise usually appears in demos from East. IM2FIX is build-in into memory extension ZX512.
top view to the case TI-of-TTL is a Timex Interface M-397 replacer, build from TTL chips only. Apart from TOS (upgraded to work with ZX128, too) in the extended memory there is ZXVGS and also keyboard test code.
TR-DOS console TR-DOS traps are needed to run TR-DOS software under ZXVGS.
  • TRETRAP - wizardly connected EPROM, has also patches to allow fast loading of "*.TAP" files; mounted with memody extension ZX512 as standard.
  • TRITRAP - mounted inside.
  • TRXTRAP - external interface.
top view YABUS.ZX is a through interface with two YABUS slots, fully connected, not buffered.
YABUS.ZXAT - AT286 main board connected as extension.
top view Z80JOY is an internal Kempston Joystick interface. The little board can be soldered over Z80, or the Z80 can be removed, replaced with a gold socket, then Z80JOY goes into it and the Z80 into the Z80JOY. The socket must be mounted somewhere on the case.
board project ZX512 is an extension to 256kB RAM, compatibile with ZX128 (option: hardware multicolor). Extension includes interrupt fix IM2FIX and the TR-DOS calls trap - TRETRAP.
ZXLED. Power switch facilitates switchind on and off the computer. The double color LED shows, whether the machine is on (green) or the power supply unit is connected (red). Also unloads capacitors in power supply unit.
  • In ZX48 (with rubber keyboard) the switch is mounted on top of the case.
  • In ZX+ the switch is mounted on right hand side, in the bottom part of case.
ZXMUX is a small board with SMD logic, that replaces 40-pin multiplekser marked PCF1306P, used at least in ISSUE 6A.
© 2004-04-04 02:14:55 Jarek Adamski zx@yarek·com, http://8bit.yarek.pl