Checking the ROM
Posted: Fri Mar 10, 2017 1:03 am
Hi,
As you may have seen elsewhere, I recently acquired some Dutch programming books. One "Zakboekje voor de ZX81" contains a ROM test listing, as follows:
There is probably a quicker way of testing the ROM, but this works (or at least it told me that I had a new ROM) - I assume that the ROM codez is the same on Timex machines also?
Regards,
Shaun.
As you may have seen elsewhere, I recently acquired some Dutch programming books. One "Zakboekje voor de ZX81" contains a ROM test listing, as follows:
Code: Select all
1 FAST
2 LET T=CODE " "
3 FOR A=T TO 8191
4 LET T=T+PEEK A
5 NEXT A
6 SLOW
7 IF T=855106 THEN PRINT "NEW ZX81 ROM OK"
8 IF T=854885 THEN PRINT "OLD ZX81 ROM OK"
9 IF T<>855106 AND T<>854855 THEN PRINT "ROM FAULT"
Regards,
Shaun.