9 replies to this topic

[Bryan]

I was looking at the XF551 schematic from J Sobola's site, and I noticed it was quite a bit different from mine. Can anyone post a picture of their XF551 main board as I'm trying to track down what the different versions were.

-Bry

[krupkaj]

I have just upgraded to HyperXF ROM, so it is not problem to make a picture

Attached Thumbnails

• 
• 

[Bryan]

krupkaj, on Sat Mar 11, 2006 6:25 PM, said:

I have just upgraded to HyperXF ROM, so it is not problem to make a picture

Cool.. thanks. Yours looks like mine (right down to the jumper because they wired the switch backwards). The schematic shows a 330 ohm resistor in R12, but it looks like you've got a 220 like me. Also, it shows a crystal oscillator circuit but we both have a one-piece TTL oscillator instead. What was your old ROM version? Mine was 7.4.

-Bry

[krupkaj]

I have it dumped here. But I do not know which bytes in image is version.

[Bryan]

I don't know how to tell either. Mine had a label that said 7.4.

The ROM looks to be half empty (or half full).

-Bry

[krupkaj]

aha, mine has EPROM without any number. And yes there is only 4 KB of code. There is also A12 of ROM connected to GND so it is in not possible to read more than 4 KB without mod. I am thinking about simple mod with switch so I can have original ROM and HyperXF in one 27C64.

Edited by krupkaj, Sat Mar 11, 2006 5:24 PM.

[Bryan]

krupkaj, on Sat Mar 11, 2006 7:22 PM, said:

I am thinking about simple mod with switch so I can have original ROM and HyperXF in one 27C64.

Good idea.

-Bry

[jaybird3rd]

I've got my '551 apart at the moment (I'm adding a 34-pin header for the floppy cable), so I'll post pictures as soon as I'm finished.

[walter_J64bit]

jaybird3rd, on Sun Mar 12, 2006 12:53 AM, said:

I've got my '551 apart at the moment (I'm adding a 34-pin header for the floppy cable), so I'll post pictures as soon as I'm finished.

What is the 34-pin header going to do for the XF551?

Edited by walter_J64bit, Sun Mar 12, 2006 1:33 AM.

[jaybird3rd]

walter_J64bit, on Sun Mar 12, 2006 1:32 AM, said:

What is the 34-pin header going to do for the XF551?

I'm replacing the XF551's very short floppy cable with a pin header, so I can plug in a standard floppy cable instead. This will make it a lot easier to mount my 3.5-inch mech, which is currently using a makeshift extension that I cobbled together.