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Re: Jazz Jackrabbit and SB 2.0 without config.sys?

OK. Weird. Having the logging adjusted to add previous CS:EIP information(only when the previous opcode was using a different code segment index/table/rpl value), suddenly the game starts like normally on the Sound Blaster 2.0? It's running at extremely slow speeds in that case... Hmmm... Each time …

Re: Jazz Jackrabbit and SB 2.0 without config.sys?

OK. Just found something weird while inspecting the SS and SP changes: MMU: Reading from real(r): 000ab480=e4 (?) Reading from RAM(r): 0010b480=e4 (?) Reading from physical memory(r): 0010b480=e4 (?) Reading from paged memory(r): 0010b480=e4 (?) MMU: Reading from real(r): 000ab481=06 () Reading from …

Re: Jazz Jackrabbit and SB 2.0 without config.sys?

OK. The interrupt handler sees that it's from segment 0x20. So it detects that it's a kernel interrupt and starts handling it like that. I see it loading a risky pointer, to the user-mode stack of the interrupted handler, with the IP? That's from FF4h and FF6h on the kernel's stack. That's pointing …

Re: Jazz Jackrabbit and SB 2.0 without config.sys?

OK. So the cause of the issue seems to be a fault where ESP=FECh, location 0020:00000c7a. The last setup of the TSS.SP0 seems to be FF8h(according to the last write to ES:[0002]). So it's at the top of the used stack at that point(perhaps having pushed only 8 bytes there somehow?). There's …

Re: Jazz Jackrabbit and SB 2.0 without config.sys?

OK. Looking upwards, I see the 0020:00000c7a being triggered normally, which is the normal #GP fault handler? ESP=FA8 when it starts. Seeing as ES=5B when it's gotten there, it was originally handling an interrupt when the issue occurs. The base of the GP(0) fault was FB4, so that's a normal Sound …

Re: Jazz Jackrabbit and SB 2.0 without config.sys?

OK. At 6MIPS it changed again when starting it: this time an exception 0xD in kernel(segment 0x20) mode? Edit: OK. I see a MOVSW instruction crashing on address DS:F6E to ES:36C6. DS=18h, so a full 16-bit range, no problems there. The other one(ES) is at offset 36C6h. It uses descriptor 5Bh. It's at …

Re: Jazz Jackrabbit and SB 2.0 without config.sys?

OK. Somehow, the samples for the Sound Blaster 2.0 seems real slow, with even some latency issues(as in repeating buffers in the recordings once in a while(each few seconds))? Edit: Also, the game starts very slowly in that case(Sound Blaster 2.0 with Sound Blaster driver enabled). Perhaps that's …

Re: Jazz Jackrabbit and SB 2.0 without config.sys?

OK. Although that seems to have fixed the IRQ crash problem(with recursive Sound Blaster IRQs), now the sound from the sound blaster sounds way too low? The time constant is loaded reversed(256 minus timeconstant) into the counter. Each 1MHz clock cycle, said constant is checked. If it's 0(finished …

Re: Jazz Jackrabbit and SB 2.0 without config.sys?

So, the issue here is that Jazz Jackrabbit seems to execute an auto-initialize DMA DAC command without ever setting up the DMA transfer properly(it doesn't set the DMA Block Count in the SB2.0). So each interrupt will be executed after only 0xAE(the set samplerate) 1MHz ticks, so after 174us. Since …

Re: Jazz Jackrabbit and SB 2.0 without config.sys?

So, the INT 0xD handler(that's triggering during the existing 0xD handler being terminated) starts as usual: ff8: sp0 base for the original IRQ0 handler to return to the never returning code ff6: IRET ss ff4: IRET sp ff2: IRET flags ff0: IRET cs fee: IRET ip (base frame for IRQ5) fec: 0h fea: Dh fe8 …

Re: Jazz Jackrabbit and SB 2.0 without config.sys?

This time, SS0 is FB4, so a different decrease should be there. It once again substracts BP from AX, but this time it gets 0xE(error code pushed) instead of 0xC(no error code pushed)! So this time it falls through the jump to CBCh, and continues on to 0020:00000c9e. So at 0020:00000c9e, the kernel …

Re: Jazz Jackrabbit and SB 2.0 without config.sys?

OK. The interrupt handler itself for IRQ5 does nothing special, just finds nothing to do, then IRETs back to B3:0002 with EFLAGS=3202. And of course that executes HLT, which traps back to segment 20h, which is supposed to handle the fault(which is a #GP(0) fault). That should be this one(line 149629 …

Re: Jazz Jackrabbit and SB 2.0 without config.sys?

ff8: sp0 base for the original IRQ0 handler to return to the never returning code ff6: IRET ss ff4: IRET sp ff2: IRET flags ff0: IRET cs fee: IRET ip (base frame for IRQ0) fec: 0h fea: Dh fe8: call IP=cc6h fe6: ??? fe4: ??? fe2: ??? fe0: ??? fde: gs ffc: fs fda: ds fd8: es fd6: 0h fd2: eax=1Ch fce: …

Re: Jazz Jackrabbit and SB 2.0 without config.sys?

ff8: sp0 base for the original IRQ0 handler to return to the never returning code ff6: IRET ss ff4: IRET sp ff2: IRET flags ff0: IRET cs fee: IRET ip (base frame for IRQ0) fec: 0h fea: Dh fe8: call IP=cc6h fe6: ??? fe4: ??? fe2: ??? fe0: ??? fde: gs ffc: fs fda: ds fd8: es fd6: 0h fd2: eax=1Ch fce: …

Re: Jazz Jackrabbit and SB 2.0 without config.sys?

ff8: sp0 base for the original IRQ0 handler to return to the never returning code ff6: IRET ss ff4: IRET sp ff2: IRET flags ff0: IRET cs fee: IRET ip (base frame for IRQ0) fec: 0h fea: Dh fe8: call IP=cc6h fe6: ??? fe4: ??? fe2: ??? fe0: ??? fde: gs ffc: fs fda: ds fd8: es fd6: 0h fd2: eax=1Ch fce: …

Re: Jazz Jackrabbit and SB 2.0 without config.sys?

OK. It then loads some data from RAM(B3:0002?), then proceeds to push the interrupted location's FLAGS on the stack, at FB2h. OK. It then loads some data from RAM(B3:0002?), then proceeds to push the interrupted location's FLAGS on the stack, at FB2h. ff8: sp0 base for the original IRQ0 handler to …

Re: Jazz Jackrabbit and SB 2.0 without config.sys?

OK. In the normal "Sound Blaster" setting it, upon reaching 0417:2308 after 0417:2307, seems to somehow be executing something which looks like a strange interrupt of some kind? Edit: It seems to be located at position 68h in the IDT, so it's interrupt Dh, thus a #GP fault or Sound Blaster interrupt …

Re: Jazz Jackrabbit and SB 2.0 without config.sys?

One thing I'm thinking about: how does the DSP busy bit on port work? When is it set or reset? Also, I notice one thing while selecting the Sound Blaster compatible setting in the setup: the information bar in Jazz Jackrabbit's (with it's HP, timing etc.) seems to be gone? As in, only the gameplay …

Re: Jazz Jackrabbit and SB 2.0 without config.sys?

OK. Just tried Jazz Jackrabbit with the same IRQ/DMA settings on Dosbox 0.74-3(the most recent one from Dosbox.com). When trying the same settings on the SB 2.0 with the normal Sound Blaster setting, it doesn't crash like UniPCemu does, but it runs without sound. When trying the same with setting it …

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