Ready to use hard disk (Flash card) image - special driver

 PPSD.IMG  is  image of complete TOS/DOS compatible hard disk partition, together with autoboot driver. Fits on drives, cards of 256 MB or larger.

 This is demonstration of what is possible to achieve with wise made SW, even on low performance machines.

About 60 games adapted for hard disk run are included. Mostly games performing floppy loadings without OS calls. Such games most be modified for running from  hard disks, flash cards in way that all floppy access code must be changed with proper hard disk access code. But it is only part of problem - we have RAM conflict problems, TOS version compatibility problems etc.

Usual solutions are oriented on using popular hard disk drivers as Hddriver. RAM conflict is resolved by swapping large RAM areas, what is slow and needs stopping of game's interrupts, music, color updates.

Things can be done better if we know how things work, and by attitude: "I can do it self best, for my needs" .

The problem with Hddriver and other popular Atari ST hard disk drivers is that they are not made for gaming. Drivers need regular Timer-C work, what many games use for own purposes, and change. Code is not relocatible, and can not simply move in High RAM. Then, they need regular TOS with all system variables, CPU vectors etc.

But for gaming is best that hard disk driver can work fully TOS independant.  This is what I made with latest versions of my drivers. No usage of Timer-C for timings - it is done with CPU code. No usage of CPU vectors, driver core is fully relocatible. Other thing needed for smooth loadings is special TOS core, for file load/saves.

The result is: disk access from games is fast, no need even to disable interrupts of game (except couple rare cases) - no flashings, no music interrupts while disk access. And all it by cost of only intelligent design. No need for some extra HW - this works with regular adapters as Satandisks, IDE adapters, CF cards, ACSI attached SCSI discs etc.

As my loadings were already fast before this, you may not notice improvement easy. Watch loadings in CREATURES - no more flashing.  Or listen to music in Heavy Metal Heroes - no interrupts.

Some may say: big noise about something irrelevant.
I think that pulling out maximum from some machine is very good thing, especially if it costs nothing.
I will not talk here about other benefits of my drivers.


This image is usable on Atari ST, STE, Mega ST(E), TT machines equipped with ACSI attached hard disks or better: Flash cards. 
Image is usable also in emulators: Steem - needs latest Pasti, and Hatari .

After everything is proper set and connected, turn on machine and wait that driver autoboots.
Then just run games on usual way. Mostly START.TOS is for it.

Dir  C:\GAMEX  :  contains couple files (shared), which are needed by most of games, to save disk space. So, keep it intact and on mentioned loc., otherwise games will not work.

Experimenting with different shared files:  if file in shared DIR is not OK, or we want to try other version of same shared file it is simple:  put it in game's DIR. Launchers will always look for file in game's DIR first, and if there no, then in shared DIR. So, may see diff. between loadings if put in game's DIR file D15R_5H.FIC from DIR C:\OLD_GOS5  . It may help too, in case of some problems.

The plan is to make image with all my adapts, based on this concept, so this is mostly test edition.   Feedback is welcome:  petari@8bitchip.info .
Usage after writing image on disk:  In case of Satandisk you need to reset ST(E) once again after power on, to achieve autoboot. Some messages will be shown.

SW for writing on SD, CF cards, hard disks. Or for making image of content, or extracting files ...

    P. Putnik, Dec.  2011.