Turning a 48K into a 128K compatible is 'just' a case of plugging in the extra RAM and an AY and adding some glue logic to get it all working. However, the timings won't be right. On the other hand they won't be that far off.
what about the heat side of it + psu ? I mean a 128 has a heatsink
So does the 48K. I didn't need to add an extra heat sink when I got my TC2048 upgraded to a Spectrum SE. The 128 isn't a very efficient design. Not sure why it puts out so much heat.
So does the 48K. I didn't need to add an extra heat sink when I got my TC2048 upgraded to a Spectrum SE. The 128 isn't a very efficient design. Not sure why it puts out so much heat.
I heard it was a dodgy voltage regulator. The Amstrad machines all use a different one which runs a lot cooler.
Seen this before. Presumably you don't have 128K basic, or 48K mode is lost forever.
How do you work that out? Part of the modification includes a two ROM set-up so you get 128 BASIC and 48K mode, just like on a normal 128. If you want the real 48 BASIC ROM in place of the modified one then you can use the Spectrum SE ROMs.
I'm planning to do that modification, but including the AY, a 32KB EPROM, and putting all the logic in a CPLD to save some space. I have already witten the CPLD logic and syntetized it into a Xilinx XC9536 CPLD. Now I have to design the PCB... :-o . My goal is to fit it all in a rubber key case.
I'm planning to do that modification, but including the AY, a 32KB EPROM, and putting all the logic in a CPLD to save some space. I have already witten the CPLD logic and syntetized it into a Xilinx XC9536 CPLD. Now I have to design the PCB... :-o . My goal is to fit it all in a rubber key case.
Are you sticking with the standard 128K or are you using the spare bits in #7FFD to 512K, or even 1MB (assuming you don't enable page locking on bit 5)? Might be worth it to run the odd bit of Pentagon software that needs more RAM.
Also, although it would be more logic, it might be worth going for more ROM banks, either in the +3 scheme or one of your own design. I can certainly think of plenty of things to fill extra ROM banks with, for example:
0 - Bugfixed UK 128 editor
1 - Bugfixed BASIC ROM with keypad routines
2 - BBC BASIC
3 - Original Spectrum ROM
4 - ZX80 emulator ROM
5 - ZX81 emulator ROM
6 - Jupiter Ace emulator ROM
7 - Bugfixed Spanish 128 editor
8 - SE Basic
9 - +3e 0
A - +3e 1
B - +3e 2
C - +3e 3
How do you work that out? Part of the modification includes a two ROM set-up so you get 128 BASIC and 48K mode, just like on a normal 128. If you want the real 48 BASIC ROM in place of the modified one then you can use the Spectrum SE ROMs.
That's good then. I'm no electronics expert, so I didn't know. I may consider this if it works.
I'm planning to do that modification, but including the AY, a 32KB EPROM, and putting all the logic in a CPLD to save some space. I have already witten the CPLD logic and syntetized it into a Xilinx XC9536 CPLD. Now I have to design the PCB... :-o . My goal is to fit it all in a rubber key case.
This project with one CPLD XC9536 exist. I can find source...
Are you sticking with the standard 128K or are you using the spare bits in #7FFD to 512K, or even 1MB (assuming you don't enable page locking on bit 5)? Might be worth it to run the odd bit of Pentagon software that needs more RAM.
Also, although it would be more logic, it might be worth going for more ROM banks, either in the +3 scheme or one of your own design. I can certainly think of plenty of things to fill extra ROM banks with, for example:
0 - Bugfixed UK 128 editor
1 - Bugfixed BASIC ROM with keypad routines
2 - BBC BASIC
3 - Original Spectrum ROM
4 - ZX80 emulator ROM
5 - ZX81 emulator ROM
6 - Jupiter Ace emulator ROM
7 - Bugfixed Spanish 128 editor
8 - SE Basic
9 - +3e 0
A - +3e 1
B - +3e 2
C - +3e 3
That's rather good. Is there much software that makes use of the additional RAM?
Starting rom with configuration menu:
8x virtual DIVIDE is emulated and each can contain different systems. All DIVIDE systems are in 512kB FLASH EPROM chip (similar as on DIVIDE PLUS rom)
Exist some games for Pentagon 256kB - 512kB or Scorpion 256kB. For example WALKER 256kB, MORTAL COMBAT, RUSSIAN ASSEMBLERS/COMMANDERS, ... http://velesoft.speccy.cz/kmsoft.htm
WALKER 256kB
STARCRAFT 512kB
IMPERIA 2 (DUNE)
IMPERIA 3 (512kB)
ATOMIC 256kB
Next free ram pages are used as TRD image (ramdisc). Exist also TR-DOS rom versions with 1MB ramdisc support then is possible from IDE (divide/mb ide) import TRD/SCL files to ramdisc and run russian software. Exist some commanders, copiers, music players with IDE access (use FAT16 and FAT32) + trdos support. High memory is also used for MB02+ memory emulation or ZX rom emulation or DIVIDE memory emulation. Profi interface support DIVIDE emulation - in 1MB memory can be up to 8x full divide systems(parallel - similar as on DIVIDE PLUS). Also RESIDOS work on PROFI if MB02 mode is active. This device is full reprogrammable. Theoretically can PROFI use hardware preakpoints as on ZX emulators on PC. Can emulate any other memory maping/paging/allram/etc...
My previous unofficial firmware for PROFI support multitasking mode (up to 7x ZX128 memory....). All is possible. DIVIDE PLUS can be emulated also, MULTIFACE, etc...
Comments
Turning a 48K into a 128K compatible is 'just' a case of plugging in the extra RAM and an AY and adding some glue logic to get it all working. However, the timings won't be right. On the other hand they won't be that far off.
So does the 48K. I didn't need to add an extra heat sink when I got my TC2048 upgraded to a Spectrum SE. The 128 isn't a very efficient design. Not sure why it puts out so much heat.
I heard it was a dodgy voltage regulator. The Amstrad machines all use a different one which runs a lot cooler.
How do you work that out? Part of the modification includes a two ROM set-up so you get 128 BASIC and 48K mode, just like on a normal 128. If you want the real 48 BASIC ROM in place of the modified one then you can use the Spectrum SE ROMs.
Are you sticking with the standard 128K or are you using the spare bits in #7FFD to 512K, or even 1MB (assuming you don't enable page locking on bit 5)? Might be worth it to run the odd bit of Pentagon software that needs more RAM.
Also, although it would be more logic, it might be worth going for more ROM banks, either in the +3 scheme or one of your own design. I can certainly think of plenty of things to fill extra ROM banks with, for example:
0 - Bugfixed UK 128 editor
1 - Bugfixed BASIC ROM with keypad routines
2 - BBC BASIC
3 - Original Spectrum ROM
4 - ZX80 emulator ROM
5 - ZX81 emulator ROM
6 - Jupiter Ace emulator ROM
7 - Bugfixed Spanish 128 editor
8 - SE Basic
9 - +3e 0
A - +3e 1
B - +3e 2
C - +3e 3
That's good then. I'm no electronics expert, so I didn't know. I may consider this if it works.
This project with one CPLD XC9536 exist. I can find source...
All this features contain my PROFI INTERFACE for ZX128+2. It's upgrade designed for use in 128kB ZX models, but can be redesigned also for use in ZX16/48kB !!!
http://velesoft.speccy.cz/profi/profi-firmware-1.htm
See documentation:
http://velesoft.speccy.cz/profi/profi_interface-high-priority_techman.zip
All components on PCB can be used in smd version as low profile internal interface.
That's rather good. Is there much software that makes use of the additional RAM?
Starting rom with configuration menu:
8x virtual DIVIDE is emulated and each can contain different systems. All DIVIDE systems are in 512kB FLASH EPROM chip (similar as on DIVIDE PLUS rom)
Exist some games for Pentagon 256kB - 512kB or Scorpion 256kB. For example WALKER 256kB, MORTAL COMBAT, RUSSIAN ASSEMBLERS/COMMANDERS, ...
http://velesoft.speccy.cz/kmsoft.htm
WALKER 256kB
STARCRAFT 512kB
IMPERIA 2 (DUNE)
IMPERIA 3 (512kB)
ATOMIC 256kB
Next free ram pages are used as TRD image (ramdisc). Exist also TR-DOS rom versions with 1MB ramdisc support then is possible from IDE (divide/mb ide) import TRD/SCL files to ramdisc and run russian software. Exist some commanders, copiers, music players with IDE access (use FAT16 and FAT32) + trdos support. High memory is also used for MB02+ memory emulation or ZX rom emulation or DIVIDE memory emulation. Profi interface support DIVIDE emulation - in 1MB memory can be up to 8x full divide systems(parallel - similar as on DIVIDE PLUS). Also RESIDOS work on PROFI if MB02 mode is active. This device is full reprogrammable. Theoretically can PROFI use hardware preakpoints as on ZX emulators on PC. Can emulate any other memory maping/paging/allram/etc...
My previous unofficial firmware for PROFI support multitasking mode (up to 7x ZX128 memory....). All is possible. DIVIDE PLUS can be emulated also, MULTIFACE, etc...