Egyptian Enterprise 64 number 2

[rubber_jonnie]

I'm not that bothered about colour. Whatever fits in best with enterprise case colouring. Or to make it easier whatever everyone else is going for.

I think Grey, and Phil and I are both going for that.

[rubber_jonnie]

@alexh @PhilC

OK I've sent over all the details and all we need now are the postal costs from him.

Please don't send over any money before I hear back otherwise it'll get complicated.

I'll let you know more as and when I do.

Thanks.

[rubber_jonnie]

OK so I have more RAM.

PXL_20261020_143342095.jpg (252.38 KiB) Viewed 28 times

Only one small issue:

PXL_20261020_144421920.jpg (323.38 KiB) Viewed 28 times

So like my other machine it may need a replacement CPU, either that or the RAM is bad. At least I know what the fix was last time and I can easily get more RAM, having spares is always useful

The case is now looking a bit more together as well:

PXL_20261020_143306005.jpg (241.89 KiB) Viewed 28 times

So all I need to do now is add some reinforcement behind in the form of UV resin and thin GRP strips and it should be good for another round trip to Egypt...

[alexh]

I would be interested in a summary of what QOL modifications you have done.

I was thinking something like this :

• ROM (EXOS 2.4?)
• Modern Voltage Regulators
• Keyboard Membrane
• Composite Mod (Might not be needed)
• RAM upgrade (512KByte? Is that the sweet spot? or is it 1.5MB?)
• Floppy Drive controller (Which I guess is what the SD card solution is too?)
• RGBS VGA/SCART cable (Needs some sort of edge connector? I think I have this cable somewhere... 3D printed shroud)
• MultiJoy adapter (9-pin joystick adapter)
• "The L2" inductor mod (reduces RGBHS/VGA shimmering)
• EPNET - Ethernet for Enterprise

[stephen_usher]

It’s a little suspicious that two machines have the same issue with the RAM expansion. Maybe the timing is very close to the edge and variations in the CPU timing per chip is enough to allow it to work or not.

I seem to remember that the Z80 in the Enterprise is an SGS part, which probably has a different mask to the Zoloft version and hence probably different timing.

[rubber_jonnie]

It’s a little suspicious that two machines have the same issue with the RAM expansion. Maybe the timing is very close to the edge and variations in the CPU timing per chip is enough to allow it to work or not.

I seem to remember that the Z80 in the Enterprise is an SGS part, which probably has a different mask to the Zoloft version and hence probably different timing.

Can't recall the make in the new machine, but fairly sure it's not the same as the one from the other machine. I will pull the CPU first I think and try the CMOS Z80 I have from one of my SBC's before I go ordering any more memory.

[rubber_jonnie]

I would be interested in a summary of what QOL modifications you have done.

I was thinking something like this :

• ROM (EXOS 2.4?)
• Modern Voltage Regulators
• Keyboard Membrane
• Composite Mod (Might not be needed)
• RAM upgrade (512KByte? Is that the sweet spot? or is it 1.5MB?)
• Floppy Drive controller (Which I guess is what the SD card solution is too?)
• RGBS VGA/SCART cable (Needs some sort of edge connector? I think I have this cable somewhere... 3D printed shroud)
• MultiJoy adapter (9-pin joystick adapter)
• "The L2" inductor mod (reduces RGBHS/VGA shimmering)
• EPNET - Ethernet for Enterprise

So from your list this is what I've done:

• ROM (EXOS 2.4?) Yes, first mod I did.
• Modern Voltage Regulators Not as yet but I may do so as I have plenty of 5v TRACOs in stock.
• Keyboard Membrane Yes, replaced one with an RWAP membrane and have another coming.
• Composite Mod (Might not be needed) Yes, to my first one, undecided about the second as yet. It's a very easy mod though.
• RAM upgrade (512KByte? Is that the sweet spot? or is it 1.5MB?)Both mine have 512KB each and I've only found one game so far that is asking for more than that.
• Floppy Drive controller (Which I guess is what the SD card solution is too?) I suspect the SD solution may be a bit more sensible than the FD controller which needs careful socket alignment, but I have built one and may build a second. The FDD controller can power both itself and the Enterprise and doesn't care if you're centre neg or centre pos which can avoid damage by pluggiing in the wrong polarity.
• RGBS VGA/SCART cable (Needs some sort of edge connector? I think I have this cable somewhere... 3D printed shroud) Just the home made VGA cable so far but I may build a SCART cable too.
• MultiJoy adapter (9-pin joystick adapter) I'm not that bothered about this one but @stephen_usher kindly gave me some edge connector to 9 pin joystick PCBs that I will be building once the edge connectors arrive. I already have the 9 pin connectors.
• "The L2" inductor mod (reduces RGBHS/VGA shimmering) This is probably next on my to-do list.
• EPNET - Ethernet for Enterprise I will have a look, but I doubt I'll bother with this one.

One last thing I'll be trying out while this machine is on the bench is RGB2HDMI but according to the RGB2HDMI instructions it requires wiring to internal ICs and can't be done from the edge connector. Should be a fun experiment.