Search found 47 matches

by Just4Fun
Wed May 24, 2017 6:48 am
Forum: Off topic
Topic: A 4$, 4ICs, Z80 homemade computer on breadboard: Z80-MBC (Mobile Breadbord Computer)
Replies: 25
Views: 928

Re: A 4$, 4ICs, Z80 homemade computer on breadboard: Z80-MBC (Mobile Breadbord Computer)

Are you planning on selling those as a kit? Hmmm... I don't think to have the time to set up a "business" on this thing. I know that it probably has some "potential market", but I prefer spend my limited spare time to "play" with other things... :lol: I want continue a...
by Just4Fun
Tue May 23, 2017 2:41 pm
Forum: Off topic
Topic: A 4$, 4ICs, Z80 homemade computer on breadboard: Z80-MBC (Mobile Breadbord Computer)
Replies: 25
Views: 928

Re: A 4$, 4ICs, Z80 homemade computer on breadboard: Z80-MBC (Mobile Breadbord Computer)

Hi all,
as "promised" CP/M 2.2 up and running on two "floppy" emulated with two 24LC1025... :D



Here more info.

Cheers.
by Just4Fun
Sat Feb 18, 2017 1:09 pm
Forum: Postbag
Topic: Just4Fun's Postbag
Replies: 10
Views: 649

Re: Just4Fun's Postbag

Some useful "Logic Level" cheap N-MOSFETs:

100pcs BSS138 (about 200mA) @ 1.25$: HERE

100pcs OA3400 (about 5A) @ 1.80$: HERE

Cheers.
by Just4Fun
Tue Feb 14, 2017 11:12 am
Forum: Postbag
Topic: Just4Fun's Postbag
Replies: 10
Views: 649

Re: Just4Fun's Postbag

Thanks Roger,
here is an other datasheet (ED060SC4 v.2): http://essentialscrap.com/eink/ED060SC4V2.pdf

I am not sure is the LB060S01 is exactly the same.
by Just4Fun
Sun Feb 12, 2017 7:07 pm
Forum: Postbag
Topic: Just4Fun's Postbag
Replies: 10
Views: 649

Just4Fun's Postbag

Hi all, it seems I've missed a new forum section... :mrgreen: So here are my two cents: Mini thermal printer: F1.jpg payed 17$ from here: https://www.aliexpress.com/item/JP-QR203-58mm-Micro-Receipt-Thermal-Printer-RS232-TTL-USB-Panel-Compatible-with-EML203/32693670343.html but in the meanwhile selle...
by Just4Fun
Sun Dec 18, 2016 5:03 pm
Forum: Off topic
Topic: A 4$, 4ICs, Z80 homemade computer on breadboard: Z80-MBC (Mobile Breadbord Computer)
Replies: 25
Views: 928

Re: A 4$, 4ICs, Z80 homemade computer on breadboard: Z80-MBC (Mobile Breadbord Computer)

I wonder why not use it at 20MHz and Z80 at 10MHz. A worth of a 20MHz canned oscillator (or a crystal) to add. Thanks Pito! I've done some tests and it seems that the "A" AVR variant doesn't like quartz on breadboard very much, so I decided for the internal oscillator. An "active&quo...
by Just4Fun
Sat Dec 17, 2016 10:42 pm
Forum: Off topic
Topic: A 4$, 4ICs, Z80 homemade computer on breadboard: Z80-MBC (Mobile Breadbord Computer)
Replies: 25
Views: 928

Re: A 4$, 4ICs, Z80 homemade computer on breadboard: Z80-MBC (Mobile Breadbord Computer)

Yes the 65c02 is a whopping $2.82... but it's a rocket ship at 10MHz :P Knocks spots off the 4MHz Z80 http://www.ebay.com/itm/1pcs-W65C02S8P-10-W65C02S8P-65C02-6502-8-Bit-10MHz-MPU-DIP40-/261988044104 .. but you can go slower.. for less.. ($1.60) http://www.ebay.com/itm/1PCS-Microprocessor-IC-ROCKW...
by Just4Fun
Sat Dec 17, 2016 9:18 pm
Forum: Off topic
Topic: A 4$, 4ICs, Z80 homemade computer on breadboard: Z80-MBC (Mobile Breadbord Computer)
Replies: 25
Views: 928

Re: A 4$, 4ICs, Z80 homemade computer on breadboard: Z80-MBC (Mobile Breadbord Computer)

ahull wrote:The needed ICs are:

Z80 CPU CMOS (Z84C00) 4Mhz or greater ($1.16)
Atmega32A ($1.70)
TC551001-70 (128kB RAM) ($1.10)
Z80 CPU CMOS (Z84C00) 4Mhz or greater ($1.16)


? Two Z80 CPUs and no ROM ?


Ops.. was a typo.. just edited..

Thanks ahull!
by Just4Fun
Sat Dec 17, 2016 9:09 pm
Forum: Off topic
Topic: A 4$, 4ICs, Z80 homemade computer on breadboard: Z80-MBC (Mobile Breadbord Computer)
Replies: 25
Views: 928

Re: A 4$, 4ICs, Z80 homemade computer on breadboard: Z80-MBC (Mobile Breadbord Computer)

Thats twice as much RAM as address space. But I presume thats the smallest RAM you can buy, or perhaps the cheapest. I quite like the Z80. I prefer it to the 6502. Yes, it the cheapest SRAM... but I have find the way to use it all... may be a new HW revision if I have the time... The Z80 is cheapes...
by Just4Fun
Sat Dec 17, 2016 9:03 pm
Forum: Off topic
Topic: A 4$, 4ICs, Z80 homemade computer on breadboard: Z80-MBC (Mobile Breadbord Computer)
Replies: 25
Views: 928

Re: A 4$, 4ICs, Z80 homemade computer on breadboard: Z80-MBC (Mobile Breadbord Computer)

Only one CPU (Z80) and no ROM!

The MCU Atmega32A "emulates" ROM, I/O for User led and User key, UART with interrupt, clock generator (@4MHz) and reset generator....

Only 4 ICs... :D

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