Forums

I owned .. (yes .. ownED , has i burned the rom :( Space harrier , which is a 256k game , according to my .sms file , The game was on 1 circuit only , no paging chip , 32 pins ..

Labeled : MPR 110-71
Pinout :

1 GND
2 NC
3 WR
4 A12
5 A7
6 A6
7 A5
8 A4
9 A3
10 A2
11 A1
12 A0
13 D0
14 D1
15 D2
16 GND
17 D3
18 D4
19 D5
20 D6
21 D7
22 /OE
23 A10
24 A15
25 A11
26 A9
27 A8
28 A13
29 A14
30 NC
31 NC
32 VCC

Now, how can this game be 256k ? and , i figured pin 1 (GND) must of been /CE since its the only chip, no selection is needed. I burned the rom by accidently applying +5v to WR :( How could the sms hand;le 256k without a paging chip ? I tried reading only the 64k available , wich produce a loading rom , but very scrambled graphics .. I thought that maybe WR could be used to be low to read 1 x 64k and high for another 64k , but the rom fried .. (i didn't have Eric's FAQ underhand ... to understand how sms' WR works..

So i'm asking ? how could this rom be handled ? 32 pins , 3 NC , 2 GND 16 adress lines and a WR in a pear tree

In this case, the paging hardware and registers are located *inside* the ROM chip. That's what the _WR pin is there for. Most SMS cartridges actually have this type of integrated ROM chip, relatively few have separate paging chips with ordinary ROMs.

There's nothing special about the SMS _WR by the way, it's just a direct connection to the Z80 _WR line, and hence active low.

Mike

SMSReader Tutorial - http://www.smspower.org/smsreader/

Author	Message
Davester Guest	256K game on 1 chip (space harrier) Posted: Fri Jan 18, 2002 3:40 am
Davester Guest	I owned .. (yes .. ownED , has i burned the rom :( Space harrier , which is a 256k game , according to my .sms file , The game was on 1 circuit only , no paging chip , 32 pins .. Labeled : MPR 110-71 Pinout : 1 GND 2 NC 3 WR 4 A12 5 A7 6 A6 7 A5 8 A4 9 A3 10 A2 11 A1 12 A0 13 D0 14 D1 15 D2 16 GND 17 D3 18 D4 19 D5 20 D6 21 D7 22 /OE 23 A10 24 A15 25 A11 26 A9 27 A8 28 A13 29 A14 30 NC 31 NC 32 VCC Now, how can this game be 256k ? and , i figured pin 1 (GND) must of been /CE since its the only chip, no selection is needed. I burned the rom by accidently applying +5v to WR :( How could the sms hand;le 256k without a paging chip ? I tried reading only the 64k available , wich produce a loading rom , but very scrambled graphics .. I thought that maybe WR could be used to be low to read 1 x 64k and high for another 64k , but the rom fried .. (i didn't have Eric's FAQ underhand ... to understand how sms' WR works.. So i'm asking ? how could this rom be handled ? 32 pins , 3 NC , 2 GND 16 adress lines and a WR in a pear tree

Mike G Joined: 21 Apr 2000 Posts: 598 Location: Newcastle upon Tyne, England	The paging chip... Posted: Fri Jan 18, 2002 9:44 am
	In this case, the paging hardware and registers are located inside the ROM chip. That's what the _WR pin is there for. Most SMS cartridges actually have this type of integrated ROM chip, relatively few have separate paging chips with ordinary ROMs. There's nothing special about the SMS _WR by the way, it's just a direct connection to the Z80 _WR line, and hence active low. Mike SMSReader Tutorial - http://www.smspower.org/smsreader/

Forums

View topic - 256K game on 1 chip (space harrier)