Add “,B” parameter to PDRIVE to Change in Resident RAM Only

This zap allows temporary ‘in memory’ change of the PDRIVE table thereby not altering the disc record.

Use PDRIVE as normal except ,B is substituted instead of the regular ,A in the PDRIVE command viz: PDRIVE,0,1=7,B.

This will alter the PDRIVE configuration in memory (you can leave the write-protect tab on) and you can do this as many times as required for the next time you RESET your PDRIVE table will not have been affected.

You could then copy SYS16/SYS onto other work discs in use.

Model I:

SYS16/SYS,02,FB

change  FE 41 21 20 06

to      C3 C0 51 00 00

SYS16/SYS,04,D4

change  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

        00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

to      FE 41 12 20 03 C3 F1 4F FE 42 C2 F7 4F 3E 41 12 77

        C5 E5 01 00 07 21 E2 4D 71 23 10 FC E1 C1 C3 F1 4F


Model III:

SYS16/SYS,02,E8

change  7E FE 41 12 20

to      7E C3 CB 51 20

SYS16/SYS,04,DF

change  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

        00 00 00 00 00 00 00 00 00 00 00 00 00

to      FE 41 12 20 03 C3 E0 4F 3D FE 41 20 F8 C5 E5 01 00

        07 21 D3 4D 71 23 10 FC E1 C1 18 E3 02



Boot In Lower Case – Model III

SYS0/SYS,11,2F

change  28 05

to      00 00


Boot in 4MHz on the Model 4 – Model 4

1. Apply this Zap using SUPERZAP:

SYS0/SYS,13,B4

change  00 00 00 00 00 00 00 00 00 00 00 00

to      3A 10 42 F6 40 32 10 42 C3 B6 48 00


2. Apply this Zap using SUPERZAP:

SYS0/SYS,11,DF

change  C3 B6 48

to      C3 A8 50


3. Execute SYSTEM,0,BJ=2


Correct date & time updating on warm boot – Model 4

SYS0/SYS,02,20

change  1E 20 0D 36 1E 21

to      19 20 0D 36 19 21


Allow the date in DD/MM/YY format – Model Unknown

SYS0/SYS,12,2B

change  20 ED

to      00 00


SYS0/SYS,12,3E

change  20 ED

to      00 00


SYS0/SYS,13,4E

change  4D 4D 2F 44 44 2F

to      44 44 2F 4D 4D 2F


Allow the date in DD/MM/YY format in the FORMAT command – Model Unknown

SYS6/SYS,12,45

change  32

to      34


Display DIRectories without Clearing the Screen – Model Unknown

SYS8/SYS,00,DE

change  CC 8F

to      21 8F