a800winplus question

[+bf2k+]

Is there anyway for an Atari 8-bit program to determine whether it is running on the 800winplus emulator as opposed to a real a8 machine? Like a value in an address?

[Rybags]

Some things don't work properly in the emulator so a program can test for such conditions:

 

. Pokey Timers are only scanline exact, not cycle exact.

. POT (paddle) registers count up by cycle on a real machine in fast scan mode - they don't do so on the emulator.

 

 

So, a short bit of code should be enough to determine the running environment.

[Rybags]

OK - short program. Only tested on Version 4.1 but should work on others.

 

EMUTEST.zip

 

(LISTed program, ENTER "H:EMUTEST.BAS")

 

The routine should return a value of 228 in the emulator, 134 on the real machine.

 

It sets the paddles to fast scan mode, then waits for a VBI to execute then waits several scanlines.

Then it starts a Pot Scan and waits one scanline plus a few extra cycles.

 

It could easily be written more efficiently - actually would do better without the NOPs then you could just have a BPL which would branch if running on a real machine.

 

0600: 68		PLA
0601: A9 40	 LDA #$40
0603: 8D 0E D4  STA $D40E  ;NMIEN
0606: AD 32 02  LDA $0232  ;SSKCTL
0609: 09 04	 ORA #$04
060B: 8D 32 02  STA $0232  ;SSKCTL
060E: 8D 0F D2  STA $D20F  ;SKCTL - enable Fast Pot Scan mode
0611: A5 14	 LDA $14	;RTCLOK+2
0613: C5 14	 CMP $14	;RTCLOK+2
0615: F0 FC	 BEQ $0613 ;  Wait for a VBI to complete
0617: 8D 0A D4  STA $D40A  ;WSYNC
061A: 8D 0A D4  STA $D40A  ;WSYNC
061D: 8D 0A D4  STA $D40A  ;WSYNC
0620: 8D 0A D4  STA $D40A  ;WSYNC
0623: 8D 0A D4  STA $D40A  ;WSYNC - wait a few more scanlines
0626: 8D 0B D2  STA $D20B  ;POTGO - start another Pot Scan
0629: 8D 0A D4  STA $D40A  ;WSYNC
062C: EA		NOP
062D: EA		NOP
062E: EA		NOP
062F: EA		NOP
0630: EA		NOP
0631: EA		NOP
0632: EA		NOP
0633: EA		NOP
0634: EA		NOP
0635: EA		NOP
0636: EA		NOP; wait some more 
0637: AD 07 D2  LDA $D207  ;POT7
063A: 85 D4	 STA $D4	;FR0
063C: A9 00	 LDA #$00
063E: 85 D5	 STA $D5	;FR0+1
0640: 60		RTS

[pps]

But don´t forget, that the emulator could pass this tests in future versions...

[+bf2k+]

But don´t forget, that the emulator could pass this tests in future versions...

Well... if a future version fixes the DCB drive cfg table, I won't need this anyway...

 

hmm.. maybe I'll setup a800 and see if that one works.

[+bf2k+]

I wonder...

Is anyone still actively developing a800win plus?

[Rybags]

I don't think so.

 

There's been a couple of "requests" threads over the last 2-3 years where we've thrown around ideas of what we'd like in it.

 

It's my emu of choice despite the shortcomings. Just a few more features like stretchable window and more accurate Pokey emulation and it would be near enough to the best emulator for any system.