Amiga 4000 ram speed ns5/21/2023 ![]() ![]() ![]() Both double and high density disk drives are supported. ![]() The floppy drive controller supports up to four devices - two attached to the internal floppy header and two connected to the external floppy port. Unlike the A1200 the A4000 has a buffered IDE port. The built in IDE controller supports two IDE devices connected simultaneously. ![]() The 5.25" drive bay's depth is limited by the power supply thus longer devices, such as CD writers and some CD-ROM drives do not fit into it. One of the 3.5" front bays is occupied with a 1.76 MB high density floppy disk drive, and one of the internal bays with an - originally IDE - hard disk drive. The A4000 has a vast array of upgrade options, including processor cards, SCSI controllers, retargetable graphics cards, video digitizers, ethernet cards and many other types of expansion. However the processor cards designed specially for the A3000 do not fit into the A4000 because of their size - the A4000's daughterboard stands in their way. The processor card slot is physically the same 200 pin one which can be found in the A3000(T). Inactive slots can be used for non intelligent cards like TBCs or fan cards. With an installed BridgeBoard two ISA AT compatible cards can be used in the remaining slots. In order to access the slots by the A4000 a BridgeBoard has to be installed. The three ISA slots have their power and ground pins activated only. The video slot is extended with 18 pins not found in previous Amiga models in order to support the AGA chip set's 24 bit colour palette. All the ISA and video slots are in line with a Zorro III slot. The Zorro, ISA and video slots are all placed on a daughterboard which is mounted vertically on the motherboard. Late models shipped with revision 11 ones. It can be replaced with revision 11, although early models have their Buster soldered to the motherboard. Most A4000s have Super Buster revision 9 chips which turned out to be having problems with Zorro III cards using DMA. The access speed of the ROM is selectable by a jumper, either 160 or 200 ns. Other screen modes require a Zorro graphics card.Īll A4000s shipped with Kickstart 3.0 ROM which can be replaced with a 3.1 one. Unlike the A3000 the A4000 has no separate flicker fixer, the 30 kHz modes are generated by the Lisa itself. Custom chipsīridgette - complex buffer Supported screen modes The access speed of the Fast RAM on the motherboard can be controlled by software, either 80 or 60 ns. The fifth socket is missing, it is replaced by 2 MB 70 ns Chip RAM soldered to the motherboard. Late models have the four Fast RAM sockets only. The SIMMs cannot be mixed and the 8 MB ones have to be placed in every second socket. The four Fast RAM sockets accept 1, 4 or 8 MB modules up to a total of 16 MB Fast RAM. The Chip RAM socket has to be filled with either a 1 or 2 MB SIMM. EDO RAM is not supported by the motherboard RAM controller, Ramsey, but some processor cards accept it and some even use its benefits. The four parity bits of the 36 bit modules are ignored and they function as simple 32 bit ones. The sockets accept industry standard 32 or 36 bit page mode SIMMs. Most A4000s have five 72 pin SIMM sockets on their motherboard - one for Chip RAM, the other four for Fast RAM. Up to 1 GB Fast RAM on Zorro III expansion cards Some late A4000/030 has its processor soldered to the motherboard leaving the CPU slot empty. The A4000/040 originally shipped with the A3640 featuring a 68040 or 68LC040 25 MHz, and the A4000/030 with the A3630 featuring a 68EC030 25 MHz and a socket for an optional 68881 or 68882 floating point unit. Most desktop A4000s' processor is located on a removable processor card. Apart from the used processor cards the two models are identical. The first models were equipped with 040 processors only, later - to fill the gap between the A1200 and the A4000/040 - with 030 processors too. In 1992 September Commodore released the successor of the A3000 based around the AGA chip set. ![]()
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