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Example:
If memory locations 1 through 3 contain 53F8EC,
the format of the hex file produced when these locations
are punched is:
:0300010053F8ECC5
Register Allocation:
Since this loader uses no RAM, all variables and data are
kept in the registers.
follows:
A - scratch
B - byte count for data field
C - checksum
D - holes the data byte
E - flag register, describes what to do next
If this register contains zero, this program is looking
for a ":" to signal the beginning of a block.
if bit 7=1, then the next character is the first digit
of a byte.
If bit 2=0, the next character is the second
digit of a byte.
1 - next byte is a count
2 - next byte is a high byte of 'the load
3 - next byte is a low byte of the load address
4 - -next byte is a type byte
5 - next byte is a data byte
6 - next byte is a checksum byte.
H, L - Load Address.
L o g i c :
The program flow is controlled by the flags in the E-
register as given above.
The registers are assigned as
Bits 0-6 have the following significance 1
IMSAI 8080
Paper Tape Loader
Program Logic
Otherwise,
address
PGM-4A
12 - 61
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