Post by dshadoff on Mar 11, 2023 16:46:06 GMT
I'm thinking about making some hardware to replicate some of Tsuushin Booster's functionality.
The truth is, I'm curious to understand what a Tsuushin-Booster based machine would actually do, and how it would operate and how a user would interact with it.
(I'm not sure how many people besides Chris himself would be able to answer this...)
From what I can see, there are three major portions to consider, and communications is only a part of what this system brings to the PC Engine (so I would prioritize the other portions):
1) The communications hardware
-> I don't know yet where this is mapped in memory, or how to interact with it... if there is any existing information out there (i.e. what port addresses, what chips are used, etc.) I'd be interested, in order to save time on the reverse-engineering.
2) Additional memory
-> From Chris Covell's page here, www.chrismcovell.com/TsushinBooster/tsussw.html , it seems that there should be 32KB of additional writable memory, mapped in banks $88 through $8B. Was this intended to be non-volatile (or battery-backed) RAM on the original ? I could easily implement that in FRAM if it is (an 18W08 chip, for example).
-> Also, of course, the ROM would need to be mapped at the usual place.
-> Was there any additional memory ?
3) Keyboard (optional)
-> This seems to be emulated in Mednafen, and based on my work with PCE Mouse replacement, I'm pretty confident I can make something which would implement this based on a modern USB keyboard.
-> HOWEVER, the original keyboard was Japanese, and had additional keys - for example, for switching between hiragana, katakana, etc. Are these necessary ? Should I base the design on a Japanese USB keyboard ? (or is it unnecessary to do so ?)
Hopefully somebody will be able to answer some of these questions with some real data. I could probably figure these things out by myself, but it would take time and may influence the priority I place on these designs.
The truth is, I'm curious to understand what a Tsuushin-Booster based machine would actually do, and how it would operate and how a user would interact with it.
(I'm not sure how many people besides Chris himself would be able to answer this...)
From what I can see, there are three major portions to consider, and communications is only a part of what this system brings to the PC Engine (so I would prioritize the other portions):
1) The communications hardware
-> I don't know yet where this is mapped in memory, or how to interact with it... if there is any existing information out there (i.e. what port addresses, what chips are used, etc.) I'd be interested, in order to save time on the reverse-engineering.
2) Additional memory
-> From Chris Covell's page here, www.chrismcovell.com/TsushinBooster/tsussw.html , it seems that there should be 32KB of additional writable memory, mapped in banks $88 through $8B. Was this intended to be non-volatile (or battery-backed) RAM on the original ? I could easily implement that in FRAM if it is (an 18W08 chip, for example).
-> Also, of course, the ROM would need to be mapped at the usual place.
-> Was there any additional memory ?
3) Keyboard (optional)
-> This seems to be emulated in Mednafen, and based on my work with PCE Mouse replacement, I'm pretty confident I can make something which would implement this based on a modern USB keyboard.
-> HOWEVER, the original keyboard was Japanese, and had additional keys - for example, for switching between hiragana, katakana, etc. Are these necessary ? Should I base the design on a Japanese USB keyboard ? (or is it unnecessary to do so ?)
Hopefully somebody will be able to answer some of these questions with some real data. I could probably figure these things out by myself, but it would take time and may influence the priority I place on these designs.