Big (but small) memory support in TinyBasicPlus

A project log for Some small computer project

Simply making small computer as a hobby, combined my previous two (ATMega, SAMD21 ARM) projects in one.

kodera2tkodera2t 01/14/2016 at 12:570 Comments

As we know, we can buy lots of single board computer with gigant memory by less than $10. In such a situation, my trial is driven by purely my personal interest. This time I made a tiny computer Arduino based TinyBasicPlus, with external SRAM to ATMega2560 through XMEM function.

You may see lots of thin jumper wires on board,,, yes :-( I could not make it in smart (non jumper) manner...

Original ATMega2560 has just 8kB but this board support 64x8=512kB (4M bits) by XMEM function of AVR. Indeed my TinyBasic source supports only one bank (64kB) of memory and still in progress but currently, as you will see, supporting around 32kB. (I need more careful arrangement in memory space) Currently this BASIC is plain one (without camera, beep RTC... etc support) but larger main memory gives more "extension" possibility. As a main memory of TinyBasicPlus, bank switching will be a bit hard one but, for example, camera application, another bank can be freely access through XMEM function. For this implementation, XMEM library developed by Andy's workshop is utilised. As same, all the information (Arduino source, Eagle files) are uploaded to github. Actual operation can be found in the following movie... have fun!