Two bank eight image ROM cartridge
This cartridge is a development from three devices/cartridges I've made in the past. The first time I made a switchable ROM was way back in the early 1990's, then, about 5 years ago I made a switchable battery backed RAM cartridge giving 2 banks of 16 images each, the BBSRAMextreme. More recently I made a very slimmed down 32K cartridge that is small to suit my Electron Ultra and it is this I want to make some changes to.
The alterations will include increasing the ROM size to 128K, giving each bank four switchable images and adding a small piano style switch to make the selection as easy as possible. I kept the board size the same and added a space to note the image names readable from the front.
The board arrived and I've assembled it, only five parts, two resistors, one capacitor , a socket and a dip switch!
I programmed the 29F010 (PLCC32) using the TL866-II-Plus with eight images and inserted into the socket.
My choice of ROM images are:
Address: Image:
00000 ADI
04000 ADT
08000 AMXSP(1)
0C000 AMXSP(2)
10000 HIBASIC
14000 HI BASIC EDITOR
18000 ADVANCED BASIC EDITOR (1)
1C000 ADVANCED BASIC EDITOR (2)
My second choices are:
Address: Image:
00000 ACP
04000 AFM
08000 WORDWISE PLUS
0C000 STARWORD
10000 STREK
14000 STARMON
18000 SHEET (part of Intersheet)
1C000 VIEWSHEET
And my third choices are:
Address: Image:
00000 STARSHIP COMMAND (1)
04000 STARSHIP COMMAND (2)
08000 HOPPER
0C000 EMPTY
10000 SNAPPER
14000 EMPTY
18000 EMPTY (These next two banks are empty so I can switch off the auto booting in to the game)
1C000 EMPTY
All four catridge slots full including the MMFS catridge.
Switch Position:
ON/ON Address 00000 & 04000
ON/OFF Address 08000 & 0C000
OFF/ON Address 10000 & 14000
OFF/OFF Address 18000 & 1C000
ROM listing with switches in differing positions:
I may make a couple of changes such as replacing Sloggers *Trek and Starspell and move the images around to suit.
All in all I'm happy with this cartridge and I'll probably use it with my other Electrons.