DSK emulation issues on BlueMSX

By maxteam01

Supporter (3)

maxteam01's picture

09-11-2019, 12:45

Hello,
I'm new to the forum.
Since I own a Philips MSX back in my younger days, I ended up in this forum which is one of the more active about MSX machines.

I'm recently testing different game dumps on different machine emulated via BlueMSX.

Except problems with some bad dump, I did not encounter particular problems with Turbo R, MSX2+ and MSX2 games.

I did not encountered any problem even testing MSX games in roms format.

The problem is the following one.

I'm testing now different DSK games which should run on a MSX machine (the first MSX in other words).

A lot of them have a one of the followinf common booting problem:
- the system boot, then the basic screen appear and then the system boot again, the basic screen appear again and the sequence repeat in a loop;
- other times the system reset asking me the current date, then the basic screen appear and the game does not start - no loop here.

For some of those games the problem was solved by booting them by setting the emulation on a MSX2 machine.

Which may be the cause of this? And there are other ways to fix this problem?
Some games does not boot even on MSX2 type machine.

Sometimes I solved the problem by pressing CTRL at boot to free some memory, but this helped only few times.

Thaks in advance.
Max

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By Manuel

Ascended (15754)

Manuel's picture

09-11-2019, 17:44

It would help if you say which disks you are trying to run and on which MSX1 machine...

By maxteam01

Supporter (3)

maxteam01's picture

10-11-2019, 00:19

The emulator is BlueMSX v 2.8.2.

THe games tested are all titles created to work on the "first" MSX.

I checked them both emulating a MSX machine and then a MSX2 machine.

THey didn't boot on the MSX one but did on the MSX2.

IN the emulation option I only swithced from MSX to MSX2 (the list contain even different localization of the machines but I always used the "normal" ones).

Thevideo frequency was set on automatic.

Here's the list of game tested:
afteroids
astro plumber
barn stormer
buster block
camelot warriors
capitan sevilla
chick figher
colony
eggy
manic miner
masters of the universe
merlin
rocket roger
stop the express
thunder ball
time curb
trantor

By Manuel

Ascended (15754)

Manuel's picture

10-11-2019, 00:30

Where did you get the disk images from? Then I can investigate...

By sdsnatcher73

Hero (592)

sdsnatcher73's picture

10-11-2019, 21:01

maxteam01 wrote:

The emulator is BlueMSX v 2.8.2.

THe games tested are all titles created to work on the "first" MSX.

I checked them both emulating a MSX machine and then a MSX2 machine.

THey didn't boot on the MSX one but did on the MSX2.

IN the emulation option I only swithced from MSX to MSX2 (the list contain even different localization of the machines but I always used the "normal" ones).

Thevideo frequency was set on automatic.

Here's the list of game tested:
afteroids
astro plumber
barn stormer
buster block
camelot warriors
capitan sevilla
chick figher
colony
eggy
manic miner
masters of the universe
merlin
rocket roger
stop the express
thunder ball
time curb
trantor

The issue is probably that these are disk conversions from tape originals. Most of these conversions were made when people got MSX2 machines with diskdrives and whilst the original software was designed for MSX1 the disk conversion may not have been tested on an MSX1 with a disk drive (as they were not very common back in the day).

For example the Rocket Roger disk conversion. The auto exec.bas starts with:

1 WIDTH 40
2 POKE -1,170

The first line switches the screen to 40 column mode, on a European MSX1 this would be the default. On a Japanese MSX1 this would fail, as it boots in SCREEN 1 and that cannot handle 40 columns. It is clearly targeted at European MSX2 machines that many people configured to boot int 80 column mode.

The second line is a POKE to make MSX1 software work on Philips MSX2 machines. There is a more generic variant (I don't remember what it is right now). But most likely this conversion originated in The Netherlands where Philips MSX2 machines were abundant.

Now if you insert the disk after the max has booted and type the following:

LOAD "AUTOEXEC.BAS"
1 SCREEN 0
2 WIDTH 40
3 POKE -1,(15-PEEK(-1)\16)*17
RENUM
SAVE "AUTOEXEC.BAS"

You now have a working disk version of Rocket Roger that works on most MSX's (I tried on a National CF-3300 and a Panasonic FS-A1GT)

By maxteam01

Supporter (3)

maxteam01's picture

10-11-2019, 22:26

Thank you,
while by myself I was continuing some tests I noticed they were game originally released as CAS for MSX (simpy by browsing MSX generation).
So I suspected they were conversion and that to be one of eht possible causes of this "problem" (which in the end is not a problem at all, mora of a curiosity).
So I believe your idea to be right.
Thanks again.

By Manuel

Ascended (15754)

Manuel's picture

10-11-2019, 22:54

If you want to play MSX1 games from disk, MSX1-Mania can be recommended.

By NYYRIKKI

Enlighted (5385)

NYYRIKKI's picture

12-11-2019, 04:10

If you feel this is interesting subject, you may want to check out:
https://www.msx.org/wiki/MSX_compatibility_problems