#garfield Logs

Apr 07 2021

12:12 AM rue_mohr: ok, its bedtime,but I'm just gonna hook up that keybaord controller before I go to bed
03:54 AM polprog: interesting
03:54 AM polprog: http://waterheatertimer.org/Names-of-parts-on-electric-pole.html
04:05 AM Tom_L: hey
09:18 AM rue_mohr: he
09:41 AM polprog: llo
09:43 AM rue_mohr: z80 seems to have verry designed around pointers
09:58 AM aandrew: it's been a while since I've worked on anything z80 but IIRC it has some nice indexing modes, kind of like 6510?
10:01 AM polprog: i remmeber my dad liked it a lot
01:47 PM rue_mohr: there are a lot of registers
01:47 PM rue_mohr: which is nice
01:48 PM rue_mohr: but looking at the instructions, I notied something didn't seem right
01:48 PM rue_mohr: the target usage for them is not x86ish
03:55 PM polprog: i was surprised to see the mcs51 have 8 general purpose registers
07:28 PM rue_mohr: yea, its funkey
07:28 PM rue_mohr: did yuo code anything yet?
07:28 PM rue_mohr: yea didn't you do a falshing led?
07:28 PM rue_mohr: external eprom?
07:30 PM Tom_L: you still have the sherline?
07:31 PM rue_mohr: yup
07:31 PM Tom_L: using it?
07:31 PM rue_mohr: I have not finished building its replacement yet
07:31 PM rue_mohr: or the other one
07:51 PM rue_mohr: a 1 meg rom is the same size as a 512k
07:51 PM rue_mohr: so, I might as well do that
07:51 PM rue_mohr: wait a sec
07:51 PM rue_mohr: no its not
07:51 PM rue_mohr: the picture lied
07:52 PM rue_mohr: haha
07:52 PM rue_mohr: the SGS thomson datasheet shows a dip32
07:52 PM rue_mohr: hahah
07:52 PM Tom_L: i started scratching my head when you said they were the same size
07:53 PM rue_mohr: pinwise
07:53 PM rue_mohr: lots of the roms are the same pin count
07:54 PM rue_mohr: so
07:54 PM rue_mohr: should I use a 2M rom and get the extra info about multi-keystrikes from it
07:55 PM rue_mohr: 27C2001
07:55 PM rue_mohr: hahah datasheet shows dip28
07:55 PM rue_mohr: er 32
07:55 PM rue_mohr: oh it is a 32
08:43 PM rue_mohr: hahah
08:43 PM rue_mohr: the 512k rom takes 125mA
08:43 PM rue_mohr: the 2M takes 30mA
08:43 PM rue_mohr: ok
09:06 PM Tom_L: newer?
09:10 PM rue_mohr: yea
09:11 PM rue_mohr: this is a bit insane
09:11 PM rue_mohr: I have 81 values
09:11 PM rue_mohr: in a rom holding 262144
09:12 PM Tom_L: who owns the rest?
09:12 PM rue_mohr: empty, I'm at 0x16970 and none of the positions have been used yet
09:14 PM rue_mohr: 1EFF0: 7F 7F 7F 7F 7F 7F 7F 7F - 7F 7F 7F 7F 7F 7F 7F 5D ...............]
09:15 PM rue_mohr: the first location with a used byte
09:15 PM rue_mohr: there has to be an optimization here
09:50 PM rue_shop1: huh, it'll have to be a 29C020
09:52 PM rue_mohr: ok, its written
09:53 PM rue_mohr: wow those are fast
09:54 PM Tom_L: not much data to write
09:56 PM rue_mohr: eproms take their time
09:56 PM rue_mohr: ok, I guess I need to go try it
09:56 PM rue_mohr: I wonder how thisone is on power
09:56 PM rue_mohr: 50mA
10:28 PM rue_mohr: I was going to need to add a transistor to know if a key was pressed
10:28 PM rue_mohr: but I made a programming error on the rom, and the codes start at 11
10:29 PM rue_mohr: and when there is no key pressed the output is 0
10:29 PM rue_mohr: so, I dont need the extra transistor
10:33 PM Tom_L: :)
11:40 PM rue_mohr: ok, I'v come up with some logical keycodes
11:40 PM rue_mohr: aka, if you press a, it uses the code for A and not some random number