RAM expansion cross-talk issues (split from: Bitshifter's Z-code interpreter)

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ral-clan
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RAM expansion cross-talk issues (split from: Bitshifter's Z-code interpreter)

Post by ral-clan »

Okay, I tried playing ZORK on my real NTSC VIC-20 today.
The RAM was provided by the Mega-Cart (32+3K).
The drive was a uIEC (Jim Brain) device 10.

The game would load well, display the title message, then an error message and RETURN PROMPT. Once it said ERROR 04, another time ERROR 01.

Here's a pic:
small01a.jpeg
After hitting RETURN at that ERROR4 [<RETURN>] prompt the VIC would do a soft reset.
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Re: RAM expansion cross-talk issues

Post by Bit Shifter »

That's a pity :(
Error codes 1 and 4 indicate, that's something wrong with the story file.
1 is for bad (z-code) operand and 4 for bad (z-code) opcode.
On real floppy drives, I would guess, it's a read error, but on SD2IEC this shouldn't happen.
Unfortunately I have no real VIC and do all testing with VICE and true drive emulation and this version ran fine with no errors.
Currently I tested the interpreter with ZORK-I, ZORK-II, ZORK-III and ENCHANTER and all worked fine.
Here are some new disk images.
Now I need more testers in order to get a hint, whether it's a bug in the interpreter, corrupt datafiles or some problems with the specific hardware configuration.
P.S.: New features: the function keys f2,f4,f6 and f8 may be used to change colors and track/sector display.
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Re: RAM expansion cross-talk issues

Post by ral-clan »

Bit Shifter wrote:That's a pity :(
Error codes 1 and 4 indicate, that's something wrong with the story file.
Would the fact my uIEC is set to device 10 instead of 8 be a problem? I didn't see any attempt to access Drive 8, though.
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Re: RAM expansion cross-talk issues

Post by orion70 »

ral-clan wrote:
Bit Shifter wrote:That's a pity :(
Error codes 1 and 4 indicate, that's something wrong with the story file.
Would the fact my uIEC is set to device 10 instead of 8 be a problem? I didn't see any attempt to access Drive 8, though.
I can answer this question: yes, definitely :) . I tried TNT's products with drive 9 in 2016, and couldn't get past the adventure intro. So you should stick to device 8 instead. Unfortunately, I cannot test Bit Shifter's version, because my current setup is a C64 with GEOS (configuring a new MPS1000 printer).
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Re: RAM expansion cross-talk issues

Post by Bit Shifter »

ral-clan wrote: Would the fact my uIEC is set to device 10 instead of 8 be a problem? I didn't see any attempt to access Drive 8, though.
No, the device number isn't a problem.
The program uses the device number, that was used to load the program.

But I think, I found the issue: The program scans the whole story file and reads track and sector information and stores them in tables.
This enables direct access to a sequential file. On "true drive emulation" and probably even more on real drives, this leads occasionally to timeouts, because the programs reads only the two bytes of track and sector link per block and then skips to the next block causing lots of head movements.
I had to check the STATUS variable and repeat the block read command for timeouts. This seems to solve the issue.

Attached are the zork images with the new version of the interpreter for the VC20 (VIC-20).
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Re: RAM expansion cross-talk issues

Post by orion70 »

:oops: Sorry if I mislead by reporting an old issue with a different interpreter.
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Re: RAM expansion cross-talk issues

Post by Bit Shifter »

orion70 wrote::oops: Sorry if I mislead by reporting an old issue with a different interpreter.
Never mind :D
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Re: RAM expansion cross-talk issues

Post by ral-clan »

Hi Bit Shifter,

I downloaded the new version of Zork you posted on the previous page (Feb 26). I noticed right away you've changed the colour scheme to a red border, etc.

Unfortunately, I still get the Error 01. Here's a screenshot:
PB050003.JPG
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Re: RAM expansion cross-talk issues

Post by orion70 »

And you're drive 8 now, are you? :)
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Re: RAM expansion cross-talk issues

Post by ral-clan »

orion70 wrote:And you're drive 8 now, are you? :)
No, I'm still using Jim Brain's uIEC as Drive 10.
My drive 8 is a real 1541, which is turned on.
If I can figure out how to, I'll copy it to a real floppy and see if it works from Drive 8.
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Re: RAM expansion cross-talk issues

Post by Mike »

orion70 wrote:And you're drive 8 now, are you? :)
Bit Shifter already pointed out, that his interpreter can cope with a device number not being 8; it defaults to the drive the interpreter was loaded from.
ral-clan wrote:If I can figure out how to, I'll copy it to a real floppy and see if it works from Drive 8.
You can use d64trans for this:

http://sleepingelephant.com/ipw-web/bul ... 65&start=7
Mike wrote:1. To write a *.d64 to disk, give its full name (including the extension) on the source device, and '#' as file name on the destination device. The target must have been formatted beforehand.

Code: Select all

SRC DEV.? 10
FILE? ZORK1.D64
DST DEV.? 8
FILE? #
This assumes the device numbers as you have stated. Set aside a pot of coffee and watch the disk being transferred. ;)
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Re: RAM expansion cross-talk issues

Post by ral-clan »

Hi Mike,

I'll give d64trans a try. The only think I don't know how to follow, according to your instructions on the other thread, is to write protect the source drive, as it's a SD-card device.
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Re: RAM expansion cross-talk issues

Post by Mike »

ral-clan wrote:I'll give d64trans a try. The only think I don't know how to follow, according to your instructions on the other thread, is to write protect the source drive, as it's a SD-card device.
Normal sized SD cards have a small switch on their side where you can set them to write protect. :)

In any case, write protecting the (removable) media in the source drive during copy operations has always been good practice. It prevents facepalms when the user got source and target drive the wrong way round. ;)
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Re: RAM expansion cross-talk issues

Post by ral-clan »

Okay, I got it transferred over to an actual floppy, and loaded it on my 1541.
Unfortunately, this time it gave me an ERROR 04.

I wonder if I'm initiating things correctly. I'm using the MEGA-CART and doing a "normal reset", and choosing the option VIC 32 +3K.
Maybe I have some bad RAM?
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Re: RAM expansion cross-talk issues

Post by orion70 »

You can change sd2iec's device number at any time if you wish to try every possible combination:

Code: Select all

OPEN1,10,15,"U0>"+CHR$(8):CLOSE1
OPEN1,8,15,"XW":CLOSE1  
But I guess it's a matter of RAM glitches anyways :mrgreen:
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