Jiffydos Vic20 issue

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repetto74
Vic 20 Amateur
Posts: 41
Joined: Tue Aug 23, 2016 10:05 am

Jiffydos Vic20 issue

Post by repetto74 »

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Hi Guys,

I have installed a switchless Jiffydos Kernal into my Vic20 (Low cost model with the external Power Block). Basically a normal power up will load the default CBM kernal while a power up with Restore key pressed will load the Jiffydos. I have installed this kind of Kernal into a C64 and working very well.
Unfortunately with the Vic-20 I do have an issue while loading the Jiffydos (in CBM mode all is working normally). As per picture I do have the screen cropped on the left side and commands do not work (i.e laoding from the SD2IEC not possible as device not found). Now the Vic20 is the PAL version and I do have soldered wires RESTORE and RESET following a guide I found for an NTSC version of the VIC but I normally assume that there should not be any difference. :?:
Does someone have a switchless Jiffydos installed with which I may check if my installation is correct? Worst thing would be a corrupted kernal then :( :?:
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tokra
Vic 20 Scientist
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Joined: Tue Apr 27, 2010 5:32 pm
Location: Scheessel, Germany

Re: Jiffydos Vic20 issue

Post by tokra »

If the screen shifts to the top and left that is a clear sign that you have installed an NTSC-JiffyDos. As you say you use a PAL-machine I assume that's why things don't work. You should first try to buy a PAL-JiffyDOS, preferably from a legal distributor like Jim Brain:

http://store.go4retro.com/jiffydos-kern ... verlay-ic/

I don't know if the ROM has other differences apart form the screen-position, but this seems likely.
repetto74
Vic 20 Amateur
Posts: 41
Joined: Tue Aug 23, 2016 10:05 am

Re: Jiffydos Vic20 issue

Post by repetto74 »

Hi Tokra,

The Vic is a PAL UK does this make a difference with other PAL systems? The Kernal ROM is normally programmed with a PAL Jiffydos as I specified when ordering it. Could it be then the difference between PAL and PAL UK? Also the screen shift is one problem on top of others like Jiffydos not detecting devices. Looks weird. :?
The NTSC Vic20 installation tutorial suggest to solder the RESTORE on either one of the two 6522 at pin 34. I may try to solder on the second one and see if it makes a difference.
Is there a guide of the soldering point for a PAL Jiffydos Kernal?
:idea:
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tokra
Vic 20 Scientist
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Joined: Tue Apr 27, 2010 5:32 pm
Location: Scheessel, Germany

Re: Jiffydos Vic20 issue

Post by tokra »

There is no special PAL-UK. PAL is PAL. The shfited screen definitely points to an NTSC-ROM - try "PRINT PEEK (36864)" - if you get 12 it's PAL, if you get 5 it's NTSC. Looks like you got the wrong ROM. I'm not a hardware-guy so I cannot say if the drive-problem is also due to this.
repetto74
Vic 20 Amateur
Posts: 41
Joined: Tue Aug 23, 2016 10:05 am

Re: Jiffydos Vic20 issue

Post by repetto74 »

Hooo man ! Print Peek(36864) will return a 5 ! :shock: :shock: :shock:
The first column is hidden due to the shift so I cannot see if something is printer before the 5 but I do see 5 :cry:
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eslapion
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Re: Jiffydos Vic20 issue

Post by eslapion »

Ya, on the C64, JiffyDOS has only one version which works on all machines, PAL or NTSC.

On the VIC-20 you must get the correct one.
Be normal.
repetto74
Vic 20 Amateur
Posts: 41
Joined: Tue Aug 23, 2016 10:05 am

Re: Jiffydos Vic20 issue

Post by repetto74 »

I have contacted the seller and he does confirm he programmed the rom with the incorrect version. It is solved I will return the kernel for a free replacement :-)
craftsman1234
Vic 20 Dabbler
Posts: 87
Joined: Thu Aug 29, 2013 3:14 pm

Re: Jiffydos Vic20 issue

Post by craftsman1234 »

Yep, looks like a PAL issue. I have the switch-less version in my NTSC Vic-20 and it works great.

I always wonder why they program them to have stock Kernal as default and JD if you hold the restore down. I have always programmed the EPROMS the opposite so they default as JD on all my Commodores.
Commodore Pet 4032, Vic-20, 2 C64, 2 SX64, PAL 64c, 128DCR. Commodore Since 1980
repetto74
Vic 20 Amateur
Posts: 41
Joined: Tue Aug 23, 2016 10:05 am

Re: Jiffydos Vic20 issue

Post by repetto74 »

Hi Craftsman,

There is a little jumper on the dual boot Kernal so depending how it is set I can have either JD or default CBM to boot when RESTORE is not pressed.
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