28th December 2020

Here is a bit more of a preview of the current boards we have on order to support ROMXe and ROMXc for the Apple IIe and Apple IIc including the production aids.

Firstly ROMXe for Apple IIe:

ROMXe supports both single ROM and dual ROM versions of the Apple IIe motherboard - if you have a single ROM machine you can break away the EF adapter part of the PCB. There are some solder pads on the underside that allow you to link them back together should you need to use the pair in a dual ROM machine again after separating them (L1, L2) :

The chip select logic supports the earlier Rev A Apple IIe motherboards as well - as yet untested but it should work :)

Next up ROMXc for the Apple IIc. This would be a great upgrade for any machine but especially one that is still fitted with the original ROM 255 as ROMXc will allow you to experment with the various 32KB ROM images that are available.

Then there is the production programming adapter which allows us to initially program the flash chips with a prebuilt image using an EPROM programmer :

Then there is the 24 pin video ROM :

The 24 pin video ROM can also be used in international boards by placing it at the rear of the 28 pin socket. The switch under the keyboard no longer has any effect in that case, but the 24 pin video ROM can store 32 character sets(!) so the switch is probably not needed.

Just in case however, we've also done a 28 pin video ROM for the international boards! The keyboard swtich will switch in a second bank of 32 ROMS! I honestly dont know if we'll use it, but at least we'll have it up our sleeve :

These video ROMs could also be used in a IIc. I think some boards may have them soldered in place in which case its not quite plug and play, but the pinout is compatible.

Then there is the production programming adapter for the video ROMs - accepts both variants and again allows production programming of the flash chip using an EPROM programmer :

And finally there is an assembly jig that is made up of 3 different PCB designs - this is used to set the pin headers at the correct length during final assembly.

So that's 9 different PCB designs (including 3 used on the jig) to support ROMXe and ROMXc. The initial batch of ROMXe and ROMXc boards will be used to further prove out the design from the hand wired prototype that we currently have running, and allow us to get the real time clock code integrated etc. All going well, we will then lay them out on a panel so we can produce multiple units as per what was done with the original ROMX.

We are both very happy and quite proud of where we got to in 2020 - starting mid year we designed and released ROMX for the Apple II and II plus and followed it up with the initial design of ROMXe and ROMXc for the Apple IIe and IIc respectively. We also managed to come up with a bit of a name for our venture - JD Micro. We're looking forward to bringing you ROMXe and ROMXc early in the new year, so 2021 is already shaping up to be a busy one for JD Micro and an exciting one for the ROMX product line :)

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