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Can a guy that traveled on the short bus learn machine code...Hmmm So after some soul searching I figured it was time to finaly nail spectrum machine code. Its so frustrating to sit infront of a basic listing w…
... test and jump based on flags. Let's take an example ...
push af
pop de ; flags now in 'e'
bit ... this example) and testing the flags register using the conditional branches ... -
Compiler conventions for passing args/return valuesI've been mulling over this for a while, but I can't spot it covered anywhere. There are various methods for passing args and return values between …
... often other registers and flags are set to communicate ... br />
pop hl
pop bc
pop de
ex ...
pop af
pop bc
pop de
pop hl
pop af
pop bc
pop de
pop hl
Compiler conventions for passing args/return valuesI've been mulling over this for a while, but I can't spot it covered anywhere. There are various methods for passing args and return values between …
... carry flag (well, all the flags) are effectively fragile, but the ... :
1) push af: pop af when needed. Requires 'a ... a push (and possibly corresponding pop at stack cleanup time, depending ...Compiler conventions for passing args/return valuesI've been mulling over this for a while, but I can't spot it covered anywhere. There are various methods for passing args and return values between …
... carry flag (well, all the flags) are effectively fragile, but the ... /> [quote]
1) push af: pop af when needed. Requires 'a ... /> [/quote]
"push af; pop af" might be an option ... called function will need to pop that parameter before it returns ...SE Basic IV Buffy v4.1 source (WIP)I've been doing a major refactor on the SE Basic source and I'd appreciate a code review from anyone who has time to look at it. I've almost certainl…
...
ld d, (iy + _flags) ; flags to D
ld c ... for meta and control
pop hl ; unstack pointer
ld ...SE Basic IV Buffy v4.1 source (WIP)I've been doing a major refactor on the SE Basic source and I'd appreciate a code review from anyone who has time to look at it. I've almost certainl…
... /> org 0x0554
sa_ld_end:
pop af ; unstack carry flag
ex af, af' ;'get flags
jr nz, ld_flag ; jump ... :
ex af, af' ;'store flags
ld b, 178 ; timing ...SE Basic IV Buffy v4.1 source (WIP)I've been doing a major refactor on the SE Basic source and I'd appreciate a code review from anyone who has time to look at it. I've almost certainl…
... loop until found
pop hl ; unstack pointer to ... 0x091e
me_old_v4:
pop hl ; unstack pointer
flags
call next_one ; get ... me_ent_3:
pop bc ; unstack length
pop de ; ...SE Basic IV Buffy v4.1 source (WIP)I've been doing a major refactor on the SE Basic source and I'd appreciate a code review from anyone who has time to look at it. I've almost certainl…
... /> fce ; exit calculator
pop af ; unstack flags
org 0x2d71 ... if not
pop af ; unstack result and flags
scf ; ...
fp_a_end:
pop af ; unstack result and flags
ret ; end ...SE Basic IV Buffy v4.1 source (WIP)I've been doing a major refactor on the SE Basic source and I'd appreciate a code review from anyone who has time to look at it. I've almost certainl…
... done
pop bc ; discard
pop bc ; stacked
pop bc ; ... pointers
pop hl ; unstack ... if so
ld hl, flags ; address flags
res 6, (hl ...SE Basic IV Buffy v4.1 source (WIP)I've been doing a major refactor on the SE Basic source and I'd appreciate a code review from anyone who has time to look at it. I've almost certainl…
... parameters
ld a, (flags) ; get flags
cp %11000000 ; ... ) ; set bit 6 of flags
jr nz, s_loop ...
ld hl, flags ; address flags
ld a, ... pop de ; unstack last op-code
ld hl, flags ; address flags ...SE Basic IV Buffy v4.1 source (WIP)I've been doing a major refactor on the SE Basic source and I'd appreciate a code review from anyone who has time to look at it. I've almost certainl…
...
inc a ; and carry flags
ret ; end of subroutine ... get_hl_x_de ; counter * dimension size
pop bc ; unstack variable pointer
pop bc ; unstack length
pop hl ; unstack pointer ...SE Basic IV Buffy v4.1 source (WIP)I've been doing a major refactor on the SE Basic source and I'd appreciate a code review from anyone who has time to look at it. I've almost certainl…
... other_str:
pop bc ; unstack second
pop hl ; string parameters ... /> pop hl ; unstack current channel
call chan_flag ; restore flags
pop hl ; restore curchl
call chan_flag ; restore flags
IF EXIST?In MS-DOS scripting, there is an IF EXIST command that lets you check wether a file exists in disk or not. There are any way to check it out from BA…
[QUOTE=Zup;730789]In MS-DOS scripting, there is an IF EXIST command that lets you check wether a file exists in disk or not.
There are any way to check it out from BASIC (without breaking the program if it does not exist)?[/QUOTE]
...IF EXIST?In MS-DOS scripting, there is an IF EXIST command that lets you check wether a file exists in disk or not. There are any way to check it out from BA…
... ,32765 ;BC=$7FFD, I/O flags address
ld a,(23388 ... ), a
ei
pop bc ;restore status
ret ...SE Basic IV Buffy v4.1 source (WIP)I've been doing a major refactor on the SE Basic source and I'd appreciate a code review from anyone who has time to look at it. I've almost certainl…
... /> call reclaim_1 ; remove spaces
pop af ; unstack token
push ...
val_fet_1:
ld a, (flags) ; address system variable
call scanning ; evaluate expression
pop af ; unstack system variable
SE Basic IV Buffy v4.1 source (WIP)I've been doing a major refactor on the SE Basic source and I'd appreciate a code review from anyone who has time to look at it. I've almost certainl…
... scanning ; evaluate expression
pop af ; unstack type
... ; checking syntax?
pop hl ; return address to ... br /> ld a, (flags) ; flags to A
and ... ) ; signal runtime
pop hl ; unstack original ch-add ...SE Basic IV Buffy v4.1 source (WIP)I've been doing a major refactor on the SE Basic source and I'd appreciate a code review from anyone who has time to look at it. I've almost certainl…
... line_addr ; get line address
pop bc ; unstack result
flags
ret ; and return
ldir ; reclaim bytes
pop hl ; unstack first location
SE Basic IV Buffy v4.1 source (WIP)I've been doing a major refactor on the SE Basic source and I'd appreciate a code review from anyone who has time to look at it. I've almost certainl…
... /> ld hl, flags ; get flags
res 0 ... /> pop hl ; unstack destination
pop bc ...SE Basic IV Buffy v4.1 source (WIP)I've been doing a major refactor on the SE Basic source and I'd appreciate a code review from anyone who has time to look at it. I've almost certainl…
... restore HL and BC
pop de ; unstack DE
... keystroke
ld hl, flags ; address flags
res 5, ( ...SE Basic IV Buffy v4.1 source (WIP)I've been doing a major refactor on the SE Basic source and I'd appreciate a code review from anyone who has time to look at it. I've almost certainl…
... ; cursor left
pop bc ; unstack count
flags
jr key_flag ; ...SE Basic IV Buffy v4.1 source (WIP)I've been doing a major refactor on the SE Basic source and I'd appreciate a code review from anyone who has time to look at it. I've almost certainl…
... /> pop hl ... pop hl ; unstack former channel address
call chan_flag ; set flags ...SCF/CCF flags - new discoveryI can't believe that no one is interested in discussing the additional, previously undocumented internal state of the Z80 CPU I have discovered recen…
... the place where the new flags are assembled before they are ... , if/when we change the flags implementation, we may well model ... each instruction that updates the flags register, but that's an ... takes the value 0 if flags change, but takes the value ...SCF/CCF flags - new discoveryI can't believe that no one is interested in discussing the additional, previously undocumented internal state of the Z80 CPU I have discovered recen…
... ] instructions that don't modify flags, not just documented instructions, and ... , the IM instruction. Behaviour of POP AF also seems of interest ... so much [I]modify[/I] flags as just restore them from ... them all. :)
And POP AF and EX AF,AF ...SCF/CCF flags - new discoveryI can't believe that no one is interested in discussing the additional, previously undocumented internal state of the Z80 CPU I have discovered recen…
... them all. :)
And POP AF and EX AF,AF ... , I will save the previous 'flags updated' state and then reset ... assignments to F and set 'flags updated' whereever they occur, and ...Sorting BusinessThis is a little bit different from the usual game-related fare but I know there are a few people here who like this sort of thing. This is about so…
... br />
pop hl
pop de
pop hl ; hl = array_lo
... />
pop de ; de = array_lo
pop hl ; hl ... a lot of flags around for choosing ...
