CHA256: Difference between revisions

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!Jumper set
!Jumper set
|-
|-
|8Mbit
|1MiB
|J5+J6
|J5+J6
|-
|-
|16Mbit
|2MiB
|J7+J8
|J7+J8
|-
|-
|32Mbit
|4MiB
|J9+J10
|J9+J10
|}
|}


A [[NEO-273]] and a LS74 are used to address C ROM. The LS74 provides the 2 most significant bits. The LS139 enables one of four pairs of C ROMs using 2 address inputs depending on which 2 jumpers are connected.
A [[NEO-273]] and a LS74 are used to address C ROM. The LS74 provides the 2 most significant bits. The LS139 enables one of four pairs of C ROMs using 2 address inputs depending on which 2 jumpers are connected.
*Max 256Mbit C ROM (8x 32Mbit)
*[[NEO-273]]
*[[NEO-ZMC]]
*LS139,LS74
==AES version==


{| class="wikitable"
{| class="wikitable"
|-
|-
!J5
!C ROM type
!J7
!Jumper set
!J9
|-
!?
|<4MiB
|J15+J16+J17+J18
|-
|-
|ROM number LSB is A19
|4MiB
|ROM number LSB is A20
|J11+J12+J13+J14
|ROM number LSB is LS74 Q2 (A21 ?)
|?
|}
|}


{| class="wikitable"
{| class="wikitable"
|-
|-
!J6
!M1 ROM size
!J8
!Jumper set
!J10
|-
!?
|64KiB
|J1+J4
|-
|-
|ROM number MSB is A20
|128KiB
|ROM number MSB is LS74 Q2 (A21 ?)
|J2+J3
|ROM number MSB is LS74 Q1 (A22 ?)
|?
|}
|}


*Max 256Mbit C ROM (8x 32Mbit)
{| class="wikitable"
*[[NEO-273]]
|-
*[[NEO-ZMC]]
!EVEN delay
*LS139,LS74
!Jumper set
|-
|1 gate
|J19
|-
|2 gates
|J20
|}


[[Category:Cartridge boards]]
[[Category:Cartridge boards]]

Revision as of 18:27, 15 January 2013

C ROMs

Up to 8 * 32Mbit ROMs (27C322) can be used for a maximum of 256Mbit. 27C800/27C160 can also be used depending on jumper configuration.

The size of largest ROM is selected using a pair of jumpers. The rest should be left unconnected.

Largest C ROM Jumper set
1MiB J5+J6
2MiB J7+J8
4MiB J9+J10

A NEO-273 and a LS74 are used to address C ROM. The LS74 provides the 2 most significant bits. The LS139 enables one of four pairs of C ROMs using 2 address inputs depending on which 2 jumpers are connected.

AES version

C ROM type Jumper set
<4MiB J15+J16+J17+J18
4MiB J11+J12+J13+J14
M1 ROM size Jumper set
64KiB J1+J4
128KiB J2+J3
EVEN delay Jumper set
1 gate J19
2 gates J20