Help me fix my grail ZX 128k Spectrum

Glenn

I'd guess it was Kempston compatible too, but seems a few used that case moulding.

Beaps

No good....

No2 (the RAM one) just makes the system reboot when I select Kingston and start the game.

Any ideas?

balford

Hmmm. Not much apart from the fact that the interface must be faulty. Does it work on any other machines?

B

Beaps

Hummm do these go bad then?

1024MAK

Yes, sometimes the chips develop faults (or more likely are killed by mis-use).

Try a simple BASIC test program:

10 LET A=IN 31
20 PRINT AT 5,5;A;" ";
30 GO TO 10

Then as you move the joystick, different numbers should be printed.

Hands off (or no joystick connected) prints 0 (zero)
Joystick up prints 8
Joystick down prints 4
Joystick left prints 2
Joystick right prints 1
Fire button pressed prints 16

Mark

Beaps

WOW ok let me give that a shot

1024MAK

And if you want some colour...

10 LET A=IN 31
20 PRINT AT 5,5;A;" ";
30 IF A<8 THEN BORDER A
40 IF A>7 THEN BORDER A/2-1
50 GO TO 10

Mark

Beaps

I typed in the first line, press enter and it beep (like an error) and highlighted the '='

I I entering it in 128 basic or 48k basic?

1024MAK

Don't forget if you are using 48k BASIC you must use the keywords entered in a single keypress, not build up using individual letters.
So for example 'LET' is on key 'L' but only when the cursor is shown as a flashing 'K'.
'IN' you get by pressing the 'EXTEND MODE' key (cursor changes from a 'L' to a 'E'), let go, then press and hold 'SYMBOL SHIFT' and then press the 'I' key :wink:
'PRINT' is on the 'P' key, 'AT' is got by pressing and holding 'SYMBOL SHIFT' and then press the 'I' key. GO TO is on the G key.

Mark

1024MAK

Until you know they work (and type), it's best to test Joystick interfaces on a 48k Spectrum rather than a toastrack or indeed any other 128k machine.

Why, well some don't work on 128k machines, for example Cursor and Sinclair Interface 2 types (and compatibles) will not work on the Amstrad produced +2A, +2B and +3 models.

Mark