Routines
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1F05: THE 'TEST-ROOM' SUBROUTINE
Used by the routines at LD_CONTRL, ED_EDIT, ONE_SPACE, FREE_MEM and TEST_5_SP.
The routine at GO_SUB continues here.
A series of tests is performed to ensure that there is sufficient free memory available for the task being undertaken.
Input
BC Size of the required space
Output
HL STKEND+BC+80-SP
TEST_ROOM 1F05 LD HL,($5C65) Increase the value taken from STKEND by the value carried into the routine by the BC register pair.
1F08 ADD HL,BC
1F09 JR C,REPORT_4 Jump forward if the result is over +FFFF.
1F0B EX DE,HL Try it again allowing for a further eighty bytes.
1F0C LD HL,$0050
1F0F ADD HL,DE
1F10 JR C,REPORT_4
1F12 SBC HL,SP Finally test the value against the address of the machine stack.
1F14 RET C Return if satisfactory.
This entry point is used by the routines at GET_HLxDE and DIM.
Report 4 - Out of memory.
REPORT_4 1F15 LD L,$03 This is a 'run-time' error and the error marker is not to be used.
1F17 JP ERROR_3
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