Later and Current Z88 Models - without the Connector
Z88 PCB connector pads tinned (no gold).
The Z88 case moulding is changed - no flap.
To our knowledge, this was never used with any external device. Earlier models had a removable flap to expose the standard 2.54mm double sided gold plated 48 pins male connector that presented all the Z80 bus signals.
On later models, when it was discovered that using this connector caused the Z88 to be unstable, the flap was made part of the case and the connector pads on the PCB were tinned, no longer gold plated.
Component P C B Side A Edge Side B GND 1 SNSL see below A11 2 +12v A12 3 A10 A13 4 A9 A14 5 A8 A15 6 A7 clock 7 A6 D4 8 A5 D3 9 A4 D5 10 A3 D6 11 A2 VCC 12 A1 D2 13 A0 GND 14 GND D0 15 D7 D1 16 M1L INTL 17 FLP (flap switch) slot 18 slot HALTL 19 NMIL MREQL 20 WRL IORQL 21 RDL MAWL 22 RESETL Resets Z88 (2 pulses required) -BT 23 SVCC 5.4v while the machine is 'on.' GND 24 SNSL
SNSL allows the machine to be automatically placed into comatose state buy causing a 'power fail interrupt' when an edge connector is plugged into to the expansion slot of the Z88.