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.