Search found 19 matches

by parc
Wed Oct 06, 2021 9:38 am
Forum: Hardware
Topic: MZ80B - BootRom Disc
Replies: 12
Views: 7614

Re: MZ80B - BootRom Disc

So, a general boot software is working and allows starting of several other software systems in the larger ROM.
by parc
Tue Oct 05, 2021 4:33 pm
Forum: Other
Topic: SB-1511 for Sharp MZ80B ???
Replies: 0
Views: 3335

SB-1511 for Sharp MZ80B ???

Has anyone a memory dump of the SB-1511 available ?

Marten
by parc
Thu Sep 09, 2021 5:15 am
Forum: Hardware
Topic: MZ80B - BootRom Disc
Replies: 12
Views: 7614

Re: MZ80B - BootRom Disc

Hey, the additional signals ( I used a CPLD to do this low level work: ATF22V10 or ATF16V8): Here parts of my CPLD code (be aware: !m1 => M1 = 1; aX => aX = 1, !aX => aX = 0 etc) /* Signals for the Boot-ROM Disc of the MZ80B */ /* 11111001 = F9 (read value at address) */ CEROM = a7 & a6 & a5...
by parc
Fri Sep 03, 2021 2:14 pm
Forum: Hardware
Topic: MZ80B - BootRom Disc
Replies: 12
Views: 7614

Re: MZ80B - BootRom Disc

Ah, yes * the software code can be found in the IPL listing starting at 05EFh * the schematic of my boot-rom is added to the message But be aware that I am not an electronic man ... PS.: The only major thing you should consider is, that the first byte of the boot ROM has to be a value of zero - so I...
by parc
Thu Sep 02, 2021 7:31 pm
Forum: Hardware
Topic: MZ80B - BootRom Disc
Replies: 12
Views: 7614

Re: MZ80B - BootRom Disc

So here is - I hope - the final edition of the card in terms of features (etc). In addition to the card shown above two changes have been made: * the iteration through the RAM/ROM disc is now possible over the whole range and not only within the 64K page size * the RAM (512 K) is now battery buffere...
by parc
Sat Jul 24, 2021 3:24 pm
Forum: Hardware
Topic: MZ80B - BootRom Disc
Replies: 12
Views: 7614

Re: MZ80B - BootRom Disc

By the way - thanks to the RC2014 community, where I got the initial YM2149/8910 schematic and from some MZ800 person, who created an new RAM file card for the 800. I have to make a second revision, because the /M1 signal has not been considered here (and that my lead to errors during IRQ handling),...
by parc
Sat Jul 24, 2021 3:16 pm
Forum: Hardware
Topic: MZ80B - BootRom Disc
Replies: 12
Views: 7614

Re: MZ80B - BootRom Disc

So, the left part is also now populated and it works. To summarize: a) The YM2149 is located at 0x60/0x61 and is feeded by the 4 MHz system clock (therefore a AY8910 will not work) a.1) One port of the YM2149 is feeding LEDs a.2) One port of the YM2149 is used for switches (for own software ) b) The...
by parc
Thu Jul 22, 2021 3:21 pm
Forum: Other
Topic: MZ80B - SP4515 as mzf available ?
Replies: 0
Views: 2695

MZ80B - SP4515 as mzf available ?

Is the SP4515 (Pascal system) somewhere available as mzf file (including the Monitor 1511) ?
by parc
Thu Jul 22, 2021 8:54 am
Forum: Hardware
Topic: Any way to improve the screen brightness of an MZ80B
Replies: 6
Views: 2955

Re: Any way to improve the screen brightness of an MZ80B

Ok, both resistor at their maximum - and I still do not see the flyback-lines.

Do you really mean, to replace ALL capacitors ? Best way to do it ? Replace one and check - then next ? Any special candidates to replace first ?
by parc
Tue Jul 20, 2021 7:36 pm
Forum: Hardware
Topic: MZ80B - BootRom Disc
Replies: 12
Views: 7614

Re: MZ80B - BootRom Disc

So, the second part of the PCB has been populated - the sound IC has been added and I get a sound, can turn on/off 8 LEDs and have some configuration switches for further project.

The third part on the PCB (left part) is actually NOT working, some kind of error somewhere ...