VOGONS


Reply 20 of 24, by Gmlb256

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ViTi95 wrote on 2021-09-16, 08:28:

That's too much RAM usage for a DOS game, think that games like DOOM just runs on 4MB.

John1985 definitely created another thread about the recommended specs for CPU and RAM.

Reply 21 of 24, by gerry

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Gmlb256 wrote on 2021-09-16, 12:33:
ViTi95 wrote on 2021-09-16, 08:28:

That's too much RAM usage for a DOS game, think that games like DOOM just runs on 4MB.

John1985 definitely created another thread about the recommended specs for CPU and RAM.

maybe the code was:

int *ptr;
//how much memory will this game need?
ptr=malloc(yes);

to use the meme.. 😀

Reply 22 of 24, by rasz_pl

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retardware wrote on 2021-09-03, 16:41:

And, don´t even think of compression to speed up disk transfers. CPUs were way too slow for that. The 80kB/sec transfer rate of PC/XT MFM disks was way faster than these CPUs could compress.

Compress no, but decompression was always faster than disk. 7MHz Amiga/Atari ST/megadrive 68000 does 500-900KB/s LZ4W

https://github.com/Stephane-D/SGDK/blob/master/bin/lz4w.txt
8 bit LZ4 variant https://github.com/emmanuel-marty/lzsa

Gmlb256 wrote on 2021-09-03, 14:19:

There are some drivers that enables DMA support on DOS but that depends of the hard disk/CD-ROM controller card and/or chipset on the motherboard.

Useless in non multitasking environment. Main benefit of DMA is ability to work on something else while transfer happens in the background.
ATA-4 (ultradma 0-3) standard and first hardware implementations (PIIX4) landed in 1997, Dos was dying by then. 1995 ATA-2 mwdma2 was same speed as pio4, and worked only on bus mastering controllers (PIIX and two broken PCI ones CMD640/RZ1000 famous for data corruption). Even Windows 95 didnt initially ship a Bus Mastering DMA driver.

Sounds like the OPs problem is not bottlenecks in DOS itself, but pains of using Linux VM to run DOSBOX in.

Reply 24 of 24, by bakemono

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rasz_pl wrote on 2021-10-11, 09:29:

Compress no, but decompression was always faster than disk. 7MHz Amiga/Atari ST/megadrive 68000 does 500-900KB/s LZ4W

Well just to be pedantic, Amiga SCSI controllers can do more than that. My A2000 with a Zorro II card does 2MB/sec.

Useless in non multitasking environment. Main benefit of DMA is ability to work on something else while transfer happens in the background.

Doesn't UDMA still have access to faster transfer rates? PIO would top out at 16MB/sec.

new retro game on itch: https://90soft90.itch.io/glamorous-zombie-flakes