VOGONS


First post, by Keatah

User metadata
Rank Member
Rank
Member

Is there any way to slow down the speed of data transfers from disk-to-memory in DOSBox? Got a few games and things that blast through their startup screens instantly and would like to slow disk access down to vintage speeds.

Reply 1 of 12, by Jorpho

User metadata
Rank l33t++
Rank
l33t++

Why not just decrease the number of cycles?

Reply 2 of 12, by Keatah

User metadata
Rank Member
Rank
Member

Then other things slow down. Just want to control disk access speed.

Reply 3 of 12, by Akuma

User metadata
Rank Member
Rank
Member

You could buy a usb-floppy drive and run the game from there 😁

Reply 4 of 12, by darry

User metadata
Rank l33t++
Rank
l33t++
Akuma wrote on 2020-06-01, 18:08:

You could buy a usb-floppy drive and run the game from there 😁

Or use a USB flash drive or hard disk through a USB 1.1 hub .

Reply 5 of 12, by Keatah

User metadata
Rank Member
Rank
Member

All the caches and block transfers, no, doesn't work.

Reply 6 of 12, by darry

User metadata
Rank l33t++
Rank
l33t++

You might have more luck with something that implements more low-level hardware emulation, such as PCEM . It emulates actual disk controllers and likely their bandwidth limitations . It won't save you from caching, but it should be able to throttle the transfer rate .

Reply 7 of 12, by Keatah

User metadata
Rank Member
Rank
Member

I was thinking of that.

Reply 8 of 12, by Akuma

User metadata
Rank Member
Rank
Member

Would setting core=normal help ? (Didn't auto have some form of block execution)?

Reply 9 of 12, by Keatah

User metadata
Rank Member
Rank
Member

If it changes anything it doesn't show any difference.

Reply 10 of 12, by Qbix

User metadata
Rank DOSBox Author
Rank
DOSBox Author

Any specific game startup screens that you are particularly interested in ?
As there is already some slowing down, but that was to prevent some game crashes.

Water flows down the stream
How to ask questions the smart way!

Reply 11 of 12, by Keatah

User metadata
Rank Member
Rank
Member

I was comparing the blue disk icon in Doom against my real hardware. A mid-range 386 and 486DX2. I rarely see it in DOSBox, but see it frequently and longer on real hardware. There's also startup status I want to see.

Reply 12 of 12, by ripsaw8080

User metadata
Rank DOSBox Author
Rank
DOSBox Author

Slowing down hard disk access can be a tricky thing to generalize, unless one is prepared to make the amount of slowness a configurable option. First, in many cases slowing down is not desirable. Second, hard disks across the DOS era varied quite a bit in performance. Third, disk cache software (e.g. SMARTDRV) could increase read speed greatly, and you can think of DOSBox as having a large and super fast cache built in.

That said, it is easy to simulate drive slowness with a small TSR program like the one attached. Just run it in DOSBox and it will noticeably slow down reads in DOS programs. You can execute the program multiple times to compound the effect if even more slowness is desired. You may find it somehow reassuring to see the disk icon flashing in DOOM, or the similar icon in Quake, but I think most people appreciate not having to wait for games to load. 😉