Changes
/* Machine comparisons */
= Machine comparisons =
====History====
*Spectrum was released in the UK in 1982. The Amstrad was released in the UK in 1984.
*Spectrum 48K sold for £99. The CPC464 with Green Screen monitor sold for £299 and with colour monitor for £399. One selling point was that the Amstrad needed only 1 plug, and that you didn't need to use the family television to use it. Also the Spectrum 48k wasn't supplied with any Monitor nor Mass Data Storage device.
* The Spectrum was designed to be used with a television, the Amstrad was designed to be used with and was sold with either a green screen monitor or colour monitor.
* The Spectrum was sold as a games machine, the Amstrad was sold more as a multi purpose machine (in the UK anyway).
* The Amstrad's BASIC and firmware are said to be better than the Spectrum's BASIC and OS functions.
====CPU, RAM and basic Harware====
*Spectrum (48K machine) has 48K RAM, approx 6.5k of this is screen. The Amstrad has 64K ram, approx 16K of this is screen.
* The CPU runs at a similar speed (3.5Mhz in Spectrum, 4Mhz in Amstrad) (Note, both systems do not run at optimum speed due to waits inserted by the video hardware).
*The Spectrum 48k can't do double buffering in hardware (the later 128K machines can), the Amstrad could from the start. On the Amstrad and Spectrum 128K you can use hardware double buffering, but then you need to sacrific twice as much video ram (e.g. For Amstrad both have a bitmapped display: 2 x 16K).
*They have a similar screen size. But Amstrad CPC actually produce smaller pixels in "equivalent" Video ModeThe Spectrum has 1 interrupt per 50Hz frame, as for the approximately same area the normal display resolution on the Amstrad CPC is 320x200 (mode 1) while ZX Spectrum produces "only" 256x192 pixels. Amstrad's screen can be reduced has 6 in size to match the Spectrum's (256x192, in Mode1) but then the actual display wondow is quite smaller as on a spectrum, with a large Border because fixed locations through the pixels have a constant sizeframe.
*Spectrum (128K model and later) and Amstrad both Neither have an AY-3-8912 sound chip. (1.7Mhz clock for AY in spectrumhardware sprites, 1.0Mhz clock for AY in Amstrad)therefore you have to use the CPU to both draw and erase the sprites.
*Spectrum 48K had a 1-bit beeper sound. Playing sounds through the beeper is very CPU intensive. The Amstrad doesn't have a beeper. The only way to simulate the beeper sound would be to convert it to AY soundhas hardware scrolling, Spectrum does not.
*The size and aspect of the pixels in the Spectrumdidn's bitmapped display are comparable t come with a joystick port, you had to buy one. There was two variants, Sinclair and Kempston, thankfully the pixels in hardware was cheap and easy to obtain, and both were well supported by software. The Amstrad's mode 1 bitmapped display came with a joystick port built in that both produce approximately square pixels.
*The Spectrumdidn's video ram takes approx 6Kt come with a tape player, you had to buy one. The Amstrad's video ram takes 16K (approx 12K when screen is reduced)CPC464 had a tape player built in, however neither the CPC664 or CPC6128 had a tape player built in, you had to buy one if you wanted to use tape based software with them.
*Both the Spectrum and Amstrad had to use the CPU for loading or saving on cassette. The Spectrum 48k can't do double buffering in hardware ROM loader used the border colours to indicate loading (especially the later 128K machines canuse of striped bars in the border to indicate each data bit)a small block for a header, and then loaded the program with one larger block. The checksum/error detection was done using XOR. The Amstrad 's ROM loader used many smaller blocks (so you could from rewind if there was an error), it indicated loading progress with text that updated on the startdisplay, and used the better CRC for error detection. On However, if the Amstrad and Spectrum 128K you can use hardware double bufferingloading messages were turned off, but then you need to sacrific twice as much video ram (e.g. For Amstrad: 2 x 16K)didn't have any indication of loading progress.
*The Spectrum has 48K's keyboard was made from rubber, the CPC had a fixed palette of 15 colours (8 colours with bright versions of each making 15 in total - LIGHT black is still black). Amstrad has a palette of 27 colours. In mode 0 you can choose 16 of these, in mode 1 you can choose 4 of these, in mode 2 you can choose 2 of theseproper keyboard. The Amstrad's palette includes equivalent colours that match closely the later Spectrum's colourshad proper keyboards too.
*The Spectrum's screen is "attribute" based. Each 8x8 cell can be assigned a background Amstrad had connections for printer, stereo sound output and foreground colour (and both colours must either be non-bright or bright)expansion. There is also the choice to flash the colours in each cell (the flash is a fixed rate It had an internal speaker, with volume control. The Spectrum 48K had connections for tape player, TV aerial and alternates between paper/pen and pen/paper)expansion. This colouring results in "attribute/colour clash" on It had an internal piezo electric buzzer, the Spectrumvolume of which couldn't be controlled. * The Amstrad's screen doesncould control the cassette motor, turning it on and off under software control to pause loading of software. The Spectrum didn't have this, you had to manually stop and there is no restriction on how play the colours can be placedtape.
*Neither had hardware sprites, therefore you have to use the CPU to both draw Spectrum and erase the spritesAmstrad both have a bitmapped display.
*They have a similar screen size. But Amstrad has hardware scrollingCPC actually produce smaller pixels in "equivalent" Video Mode, as for the approximately same area the normal display resolution on the Amstrad CPC is 320x200 (mode 1) while ZX Spectrum does notproduces "only" 256x192 pixels. Amstrad's screen can be reduced in size to match the Spectrum's (256x192, in Mode1) but then the actual display wondow is quite smaller as on a spectrum, with a large Border because the pixels have a constant size.
* The size and aspect of the pixels in the Spectrum was designed 's bitmapped display are comparable to be used with a television, the pixels in Amstrad was designed to be used with and was sold with either a green screen monitor or colour monitor's mode 1 bitmapped display in that both produce approximately square pixels.
* The Spectrum was sold as a games machine, the 's video ram takes approx 6K. The Amstrad was sold more as a multi purpose machine 's video ram takes 16K (in the UK anywayapprox 12K when screen is reduced).
* The Spectrum didn't come has a fixed palette of 15 colours (8 colours with bright versions of each making 15 in total - LIGHT black is still black). Amstrad has a joystick portpalette of 27 colours. In mode 0 you can choose 16 of these, in mode 1 you had to buy one. There was two variantscan choose 4 of these, Sinclair and Kempston, thankfully the hardware was cheap and easy to obtain, and both were well supported by softwarein mode 2 you can choose 2 of these. The Amstrad came with a joystick port built in's palette includes equivalent colours that match closely the Spectrum's colours.
* The Spectrum didn't come with a tape player, you had to buy ones screen is "attribute" based. The Amstrad CPC464 had Each 8x8 cell can be assigned a tape player built background and foreground colour (and both colours must either be non-bright or bright). There is also the choice to flash the colours in, however neither each cell (the CPC664 or CPC6128 had flash is a tape player built fixed rate and alternates between paper/pen and pen/paper). This colouring results in"attribute/colour clash" on the Spectrum. The Amstrad's screen doesn't have this, you had to buy one if you wanted to use tape based software with themand there is no restriction on how the colours can be placed.
* Both The colours of each 8x8 "attribute" cell is defined by a block of ram following the Spectrum 's bitmapped screen, each byte represents one cell and Amstrad had to use the CPU for loading or saving on cassetteeach byte defines paper colour, pen colour, flash enabled and bright enabled. The Spectrum ROM loader used the border colours to indicate loading (especially for the use of striped bars in pens on the border Amstrad are defined by writing to indicate each data bit) a small block for a header, and then loaded the program with one larger block. The checksumGate-Array's palette I/error detection was done using XORO registers. The Amstrad's ROM loader used many smaller blocks (so you could rewind if there was an error), it indicated loading progress with text that updated on pens are read from the display, pixel data and used the better CRC for error detection. However, if resulting colour is looked up in the loading messages were turned off, you didn't have any indication of loading progresspalette registers.
* The Spectrum can display all 15 colours on the screen. The Amstrad's BASIC and firmware are said to be better than can only do the Spectrumsame in mode 0, but this has fatter pixels. If the CPC's BASIC and OS functionsmode 1 resolution is chosen, this is not possible because only 4 colours can be chosen.
* The Normally Spectrum 48K's keyboard was made from rubbergraphics is stored in 2 colours, the CPC had a proper keyboardwhich means 8 pixels for each byte. The later Spectrum's had proper keyboards too. * The In Amstrad had connections for printermode 1, stereo sound output and expansioneach byte defines 4 pixels. It had an internal speaker, with volume control. The Spectrum 48K had connections So for tape player, TV aerial and expansionthe same graphics you often need twice the RAM on the Amstrad. It had an internal piezo electric buzzer(This is a case where graphics without transparency are used). If transparency is used, then the volume amount of which couldn't data can be controlled. * The Amstrad could control the cassette motor, turning it on and off under software control to pause loading of software. The Spectrum didn't have this, you had to manually stop and play the tapesame.
* The Amstrad's screen size and position can be reprogrammed, the Spectrum's screen size and position is fixed. It is possible to program the Amstrad's screen to use the entire monitor display area (at the expensive of approx. 22K of video ram being used).
====Sound====
*Spectrum (128K model and later) and Amstrad both have an AY-3-8912 sound chip. (1.7Mhz clock for AY in spectrum, 1.0Mhz clock for AY in Amstrad).
*Spectrum 48K had a 1-bit beeper sound. Playing sounds through the beeper is very CPU intensive. The Amstrad doesn't have a beeper. The only way to simulate the beeper sound would be to convert it to AY sound.
NOTE: The Spectrum was acquired by Amstrad after the Spectrum 128K had been made. Amstrad then improved the build quality and enhanced it. The result was that the Spectrum +2, was closer in looks and build to the CPC464. The Spectrum +3 was similar to the Amstrad CPC6128 because both had a internal 3" drive. The overall hardware of the Spectrum didn't change, the graphics was the same, the sound was the same, but the later Spectrum's had built in joysticks, built in cassette or disc, connections for printer etc, all which the Amstrad had starting with the CPC464.
